I witnessed something which I thought was unique, but might be known behavior to some of you guys out there. I just thought I’d share.
I have a yearling Rinkhals (Hemachatus haemachatus). He is an absolute character and gets up to all sorts of antics in his cage.
One of the things that he was doing, was to put the front part of his body into his water bowl, pushing his head up and down and around in the water bowl. He was basically swimming with his head under the water. He was not just lying in the water, and it seemed as if he was searching for something in the bowl. A friend of mine suggested that I put a gold fish in there, to see if he eats it. I know in nature they eat a lot of frogs, and I managed to get some tadpoles which I then placed in his bowl. 
I then thought he would try and corner them under the water and catch them. He did put his head in the water and just kept moving around, with the tadpoles being too fast for him. I then thought I misunderstood his behavior, because he was clearly not fast enough to catch a tadpole. He kept on doing this, and I eventually realized what he was doing. He was chasing the tadpoles, making them jump out of the water, and then eating them on the outside.
As he was continuously moving his head around the water, and every now and then stops, and does some searching around the water bowl. He knows he can not catch them in the water, but he chases them out of the water, and then catches them.
This must be an instinctual behavior, as he did this from the word go. So I suppose in nature in small puddles where tadpoles reside they would behave like this. Unfortunately, I did not have my camera at hand to film this, but I will try to film this in future. Amazing creatures.
