Dolphins sleep with one half of their brain at a time so they can keep one eye open to watch for predators. Dolphins sometimes work together to attack a shark that is threatening the group.
There are 50 kinds of sea snakes in the Indian and western Pacific Ocean. They live on fish. Snakes are much more dangerous to people than sharks - in fact, it has been estimated that snakes may cause 100,000 human deaths a year. Snakes don't blink because they have no eyelids.
For gorillas the juicy fruit, leaves and stems of a rainforest diet, together with dew, usually provide all the water they need.
Lions usually hunt at dusk, resting and sleeping during the day. Males let the females do most of the hunting for them.
Tarantulas only attack humans if provoked. Their bite is usually no worse than a bee sting.
Bears eat almost anything, including spiders, insects and lizards. American grizzly bears are particularly skilful at fishing. In autumn they scoop up salmon that are swimming up the rivers to spawn.
A giraffe's tongue is up to 45 cm long and it's blue-grey. Giraffes can use their tongues to clean their noses as well as their ears.