I ask this question as my little tadpoles (half a million of them!) have been frantically busy in the wildlife pond, little tails lashing in a feeding frenzy so that they have little rafts of bubbles above them. You would think that by nightfall they would be exhausted, but no - I went out to satisfy my curiosity last night, as to where there sleeping quarters were - the shallow bit which stays warm or the deep bit where they feel safe from predators? Well, as I shone my little torch on them they were still having fun all over the pond, shallow bit and deep water, just as if it were day. In fact, 7 Palmate newts had come to join them and were doing a slow-motion march around the shallow pond shelf. They seemed unbothered by the light - almost as if they hadn't noticed at all!
Anyway, they must, at some point in the night, gather together perhaps in the floating undergrowth of the pond, as it takes a while for them to gather again in the shallows in the morning. I'd never thought of Tadpoles keeping late hours and partying like there was no tomorrow. Makes me smile though!