Ant bites could definitely have done it. They can kill not only small animals (the spread of ants is responsible for the virtual disappearance of horn toads) but also newborn calves. A friend of mine's mother fell in a field and was unconcious for awhile, got bitten badly by ants, and finally died from complications from the bites! They are vicious.
But it might have been something else entirely. Maybe he was ill and just didn't show it. It's hard to say.
I don't know if there's an appropriate age for letting a turtle out to enjoy the sun. They really do enjoy it and it's good for them too. Maybe one of the moderators can help.
I used to put my turtle in a small tank - a 10 gallon one - while I was cleaning his big tank. When it didn't have water in it he tried constantly to climb the sides, then would fall over on his back, and I knew that wasn't good for him. Maybe if I had put water in the tank it would have been ok. Now, I rotate him between his indoor tank and his outdoor pond when I'm cleaning one or the other, or else let him walk around outside (while I'm watching constantly).
I hope you get another RES. You sound like you'd provide a great home for him/her.
) are so wonderful. A true animal loving sight!
