I noticed that my female red eared slider, Cinderella, was looking a little bit bigger since I last measured my turtles size about three weeks ago. And so I picked both my turtles up and compared them side by side like so:

This is a painted rendition (through Paint.net) of two different older pictures. I didn’t actually take any photos of the incident.
pet RES turtles plastron to plastron painted

So anyway, I held my turtles up plastron to plastron (or bottom/belly shell to bottom/belly shell) and noticed that Cinderella had indeed grown and that she was now a little bit bigger. Very quickly, she stretched her whole neck and angled her head downward, kinda like so:

how my pet turtle bit my other red eared slider turtle

…and she delivered a very quick bite to the face of poor Rex. She bit his face!! I was so shocked.

I immediately got flashbacks of how she had been mean to him in the past:

  • While Rex would bask, she would purposefully go to him and push him off the platform
  • While Rex would do anything peacefully, she’d come over and push him
  • She’d go up to him, only to swim away and kick him in the face
  • Many, many attempts to bite him his legs, tail, and face

Rex managed to get even by eating more food at feeding time – which I thwarted by feeding my turtles separately.

After noticing that almost every time I watched them there was at least one bite attempt, I decided it was time to keep the pet turtles separated for good before one of them lost a tail or otherwise drew blood. I can see that there is no chance that I’m going to ever keep the turtles together in the future.

Rex’s chin/throat area was a light pink from the bite. I put them both down and gave Rex some treats (freeze dried crickets!!). He was very scared to eat them by hand, which is how I usually give them, so I left them on the water for him to eat.

Rex is fine now and is swimming around like a happy turtle.

Now his throat/chin area is slightly pink, with a tuft of loose skin (looks like shedding) right over the spot. It looks like he has a goatee!!

Here are some pictures of Rex several hours after he got bit on the face by Cinderella, my female red eared slider. Please note that it is very difficult to take accurate looking photos. Without the flash, the photos are too dark and blurry. With the flash, everything looks brighter and whiter so you can’t see the pinkness or the bunch of loose skin on his throat area that looks like a goatee. This means that the bite area/pink area and loose skin on the throat look a lot less in terms of both color and quantity – and you almost can’t see them. Because the flash drowns out the details, I added arrows to each picture to help identify the pink areas/ loose skin goatee.

(you can see some later and better photos here: pet red ear slider turtle’s bite mark)

And that’s why I continue to keep them separated.


  1. Thanks for sharing. My smaller sized turtle used to bite on my bigger one’s turtle. The big one hardly fight back until recently. I notice the smaller sized turtle was injured here and there. Therefore, I was thinking to replace with a bigger tank. After reading your post, separating into 2 tank is the best solution for both! Thanks for sharing!

    1. you are welcome, Jumbodogs!!

      Separation is the best way to reduce aggression other than getting a really, really big pond!

      What kind of turtles do you have?

  2. Hey, I have a quick question. I have two turtles, they are both very very young. One is much bigger than the other and bites the little one on the tail, which is a little nub since the day we got them. He’ll bite the tail and then pull him off the basking rock and into the water and just hold him there like he’s torturing him! But this is the ONLY aggressive thing that happens! They will bask together and the big one allows the little one to sleep on his back. What do you think is going on? Should I separate them?


      1. this seems a little extreme for turtles my turle bites my other turtle all the time. Its part of mating. Only seperate them if they draw blood or if you don’t want to have babies. -_-

        1. some turtles do bite during mating. If your turtles bite only when they mate, then… well, you probably deal with a lot of eggs

          otherwise, it’s a sign of aggression, not love

  3. Hey i have da same situatuin herer nd i need some help??? i went to da veterinarian nd they told that maybe im not feeding them nd well i feed them evryday with all types of turtle food….. but my female turtle is biting my male turle foot nd i had to seperate them before she tears his foot LoL!!!!


    1. Hi Travieza, there is only one solution to stop the biting – your pet turtles need to be physically separated. there’s no other way about it. Turtles, red ear sliders in particular, are territorial and will fight other turtles.


  4. i have two res and they get along great. they bask together share there food and sit real close when they sleep.

  5. I have two pet yellow sliders and the female bite the male badly the mouth and nose and eye area I sperated them and the male isn’t eating. do u have any advise on what to do to get the male healty again? PLEASE HELP

    1. how bad is the pet turtle bite damage? If it is very bad take your pet turtle to a qualified reptile vet right away.

      Otherwise, your male turtle will heal quickly and will resume eating after a little while.

  6. I have a 5 year old turtle and he is a male.I want to buy him a female turtle.My turtle is a red eared slider and he likes to eat all the time.My question is ,if buy him a female turtle , will my turtle be agressive to the other turtle since they don’t know each other? Please can anyone tell me what to do.

    1. depends very much on their personalities, so hard to tell for sure. It helps to have a really, really large turtle tank.

      Do you plan to breed them? With so many red ear slider turtles mass-produced out there it’d be better not to.

  7. I have a varity of pet turtles, in a very large pond. I have two male reds that will not get along during feeding time. If the one eats he will be bitten on the back of the neck and he draws blood and skin. It is out of control I don’t know what to do? I have netted him while the other one eats , but know he is to big to net. So now I remove him during feeding time ( sort of teaching him a lesson) Now the biting is more severe if he caughtes the other one. I afraid that he will die if I keep them together with the other seven turtles. What to do? Any ideas?

    1. wow, that’s a tough situation!

      Is there any possibility to permanently separate the two turtles? Maybe keep one indoors in a turtle tank?

  8. HI! I have a male & female RES. The female is 4 mos older than the male (1yr old and 6months old). The problem is that, my female turtle is biting the little one on his shell ( left-lower part of the shell) and on his left foot, and tail. I already saw this a couple of times. But there is no scar or bruises. I’m very worried for my male RES. But they share the same bassking area, sometimes the little one is on her top. I know they are friends.

    Another thing is that. My male turtle doesn’t eat turtle food. What he wants is a cat food ( friskies), Its kinda weird but that’s what I gave him. Sometimes he tries eating Dried shrimp, but only one or two pieces.

    what should I do?

    1. Your pet turtles need to be separated. Red ear slider turtles are territorial and will usually tolerate each other while basking. There may be no visible scars or bruises now, but it will not be long before skin damage starts and your male red ear slider loses his tail or an eye…

      Also, it’s possible that the female might be intimidating your male pet turtle. I would suggest trying to feed them in a separate container by themselves.

  9. i have a male red ear slider and he is biting my yellow bellied cooter on her shell and on now on her web foot on the right why is that and i just purchased her on sat the 5th of march and i think he is being agressive towards her and she is 6 inches and he is 5 and a half what do i do

    1. red ear slider turtles are territorial by nature. This gets worse in captivity as there is less ‘space’ available in the habitat. The only way to stop it is to completely separate them. There’s no other way unless you get a really, really large turtle pond

      1. I have a 800 gallon pond in my back yard but my turtles still fight, one is having trouble walking due to the biting.. We give walter a time out when we catch him biting roxie. Not having enough space shouldn be a problem. I guess we will have to rotate pond time now.. They both eat good and will bask on the big rock in the middle of the pond.. Having trouble finding a vet that knows about turtles.. Will try to take walter to the vet when i find one..

  10. I originally had a red eared slider turtle but then rescued another red eared slider from my aunt. The new one is tiny and ive noticed bleeding from its right foot and missing nails.I put neosporin on it but then today the other foot is bleeding and is missing nails! I quickly took it out immediatley and freaked out!! I quickly realized the bigger ones had been chasing it but i never out much though into it.Im thinking the bigger one is biting the little ones leg. Should I divide the turtles tank? Or separate them for good? HELP PLEASE!!!

    1. you can divide the tank (make sure that neither turtle can cross over) or completely separate them in different turtle tanks – it’s up to you.

      Either way, do it quick!!

  11. i have 2 red eared sliders, and lately i’ve been noticing that the male has been biting on the female. she’s alot larger than my male, he trys the mating ritual and trys to mate with her, shes just not letting him….she layed eggs once before, so i know they mated before, but now i noticed she may not be interested in him, and now hes biting her, he simply wont leave her alone. what do i do, he keep biting her in the same spot so i took him out, what do i do? Can u help, thanks

  12. Back in February I got two red eye turtles. I have a tank,filter,the right light ect. but one of them has been growing a lot faster then my other one. I can’t tell if they’re male or female..one of them is the size of my palm and the other is half his size or a bit bigger then that. For the past week or so the little one hasn’t been eating or i just haven’t seen him eat. the bigger one eats like a pig so i try to cut down of his food. They’ve always gotten along with each other…i have a rock where they lay above the water ,they have so much room but they end up on top of each other haha. i’ve tried taking out the bigger one so the smaller one can eat but that hasn’t worked. i don’t know what to do.. he sleeps a lot more or stays at the bottom of the tank under a rock where my ghost shrimp and bottom feeders like to hang out and just swims around.

  13. WOW I am glad that I read this I was trying to find some info. I have had my RES for over 10 years now. The female is so big. She is twice the size of the male. I have not seen one as big a my female before. She is all of about 13 inches long and they use to be the same size when i got them when they were babies. He use to bite her all the time but she was big it did not really do anything now she is biting him and she is scaring up his shell. I am going to separate them for a while or get a bigger tank and see if that works.

      1. Hey forlogos, I have two large RES and i have them for one year now how can I tell if one is a female or male?

  14. hi :o) I have two map turtles a female and male and a good set up the female is bigger than him they have been in the same tank for about 9 months, he rubs shell with her alot but nothing more, but I see her biting his shell today it got quite bad so I took him out he is walking around the front room at the mo is that normal, I’ve read alot on males biting
    kind regards

    1. if it gets worse, separate them. You mentioned rubbing shells – if they are in a small tank, separate your pet turtles

  15. Hi. I have a 4 year old Western Painted that has been alone for the last 3+ years, she’s 6 inches long. Today we bought a RES from the local pet store. “He’s” 4 inches. She won’t stop bullying “him”. She bites at his feet and tail and shell. I have been separating them. He’ll be staying the night in a plastic tote since I can’t trust her to be nice without supervision. I understand that they’re territorial, but is there anyway to get this behavior to stop without constant separation? Chances are if I can’t get this worked out in the next few days our new little guy will probably go back to the store. 🙁

  16. Hey all

    I got 2 yellow belly turtles and 2 new musks which are fully grown. New tank new set up and it seems one of them has bitten one of the musks tail off. He nw seems to sit by himself all the time and barely eats. When I bought them in the shop they said nothing about aggression at all. It’s awful please advise

    1. so sorry to hear that… Figure out which turtle is the aggressive one and permanently separate that one from the rest. My hunch is that the aggressive turtle is also eating most of the food. In the meantime, separate the injured turtle during feeding time so that it can eat in peace

  17. I have two yellow bellied sliders (one is about 9 inches and the other 4 inches). The smaller was missing it’s right front leg when we found it (it was the size of a bottle cap at the time). We were told we could put them together once the smaller one reached 3-4 inches so we did. They had been together in a 100 gallon tank for about a month. We kept a close eye on them for the first few days and they got along great (the little one would even hang out on the bigger ones shoulder and they would bask together without a problem). Today we noticed the bigger one pecking at the little one when we got home from work and immediately seperated them. Upon closer inspection, we’ve noticed the bigger one had bit off both of its back legs (now it only has one useable leg) and half of its tail. There isn’t a certified reptile vet close by or open that we can get to. PLEASE, PLEASE advise on what to do as I don’t want the little one to suffer unecessarily. Thank you in advance for any help you can offer.

    1. sorry for the late reply… by now the wounds should’ve healed already. I hope you’ve permanently separated them!

      How is the little turtle doing?

      the little turtle can no longer swim – it may still want to bask so do provide water, but be sure he can’t drown. He also can’t turn himself right side up if upside down, so make sure he can’t flip himself too.

  18. hey i just got a baby res and a map turtle and the map is alittle bigger he sometimes nips at the red eared slider and sometimes nips his own arm what should i do?

  19. Hey forlogos nice post man. I also have 2 red eared slider turtle. But, they don’t bite each other while eating or while roaming in my house. I love them too much :D. Its good for me.. hehe

  20. Sorry to hear that your turtles couldn’t get along. I have two baby turtles right now, and they seem to get along fine, though one of them spends most of his day in the water, and the other spends most of his day hiding behind a plant on the other end, only occasionally coming out for a swim. I hope my turtles continue to be friends and can continue to live together.

  21. hi i have 4 baby red eared sliders about 1 and a half inches in a little island tank from downtown Los Angles until i make their tank on Friday………well i don’t know if they are male or females but my little sister told me that one of them bit the other’s leg………no serious injury…. nothing happened…but i am afraid to put them in my 10 gallon tank because i dont want them to tear each other up……..they are separated now…..but i am concerned on why are they doing this……….they never did this and I’ve took en care of them since a month now….i think ever since they ate a guppie’s (a fish) tail they are acting strange…..PLEASE HELP ME

    1. the small they’ve been in have no doubt pushed them to be aggressive to each other. Besides separation, more room would be the best way to reduce biting

  22. I’m late so I don’t know if you’ll check this but I have 3 turtles…2 of them get along fine…Bask on top of each other…enjoying life…I can even hand feed one and she’ll never bite me, only food (even the little pellets) The bigger one, who was abused, has to stay separated because if I put her in the tank for more than a 10 seconds she’ll start biting at the others…not even soft bits, but at the shell…so I have to keep her separated as well…It’s odd though because she isn’t aggressive in any other way and is actually rather shy. My aggressive turtle is the only one I bought from a pet store…one was a rescue (the big biter) and the one that eats out of my hand was a “gift”

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