I've photographed and watched them in the wild.They can snap off a broom handle with their teeth; I can attest to that. I'd treat them with absoulte caution for this reason; I would think that you'd need a properly-enclosed outdoor pond that they could not burrow out of; unless you had a tank with a huge floor area; since I have seen snappers that exceeded 14 inches in length..! I will try to dig-up the photos that I took of a huge one that my husband foolishly picked up (hey, it was awhile ago.. lol.)