They are much better left in the wild or in well looked after breeding colonies in Zoos and Aquaria. Remember that nearly all species are endangered to some extent or another. The largest living penguins are the Emperors. Emperor penguins stand around 1.2metres tall and weigh around 40kg. Different species of penguin sleep at different times and in different ways.
Most penguins only take short naps.
It certainly is not a stupid question to ask whether penguins have tongues. In fact all birds have tongues of some sort or another. Penguins have very specialised tongues that are rarely seen since they don't extend out of the beak. Penguins tongues are covered with lots of little spiky spines that all point backward into the throat so that when a penguin catches a fish it is gripped by the spines and cannot escape. Different species of penguins can swim at different speeds.