sick or clumsy?

[kiwi axolotls]

i’ve noticed my axie seems to have chunks being taken out of his tail? he’s in a tank on his own so i know nothing is attacking him. there’s nothing sharp in the tank to do it. could he be biting himself???
he’s very active at nice so maybe possibly he damaged himself then i don’t know!!!!

 

[AMurry24537]

i’ve noticed my axie seems to have chunks being taken out of his tail? he’s in a tank on his own so i know nothing is attacking him. there’s nothing sharp in the tank to do it. could he be biting himself???
he’s very active at nice so maybe possibly he damaged himself then i don’t know!!!!

Mine keeps doing the same thing too! Similarly, nothing sharp, only creature in his tank. A while ago, I did replace his hide though, and it seemed to help; I was thinking that maybe he was getting his tail stuck underneath it somehow (it also had no sharp edges), and since then, he's only had small chunks go missing. I replaced it with a sanded-down pvc pipe. There are still small chunks missing every so often, but I'm hoping that, once I move him to a larger tank, it will happen less or not at all. In the meantime, I'm making extra sure his water/tank is super clean to help with healing.