Giraffe bulls are so large, they can put their head through the window of the second floor of a building and say "hello". Their tongue is up to 50 centimeters long, is desensitized to prickly leaves, and has an unusual color: it is dark blue. This color helps protect it from sunburn when giraffes use it to wrap around and pluck leaves. Even animals as large as giraffes need to sleep between meals. When there is no threat of danger, they lie down for a nap, but in the wilderness they mainly sleep standing up.