Zzzzzz

Here's something really interesting. Did you know that hibernating animals have to wake up periodically during the winter - to sleep? I always thought "mmm, they get to sleep for six months straight, sounds nice." But apparently hibernation is below the level of sleep, metabolically. Their brain activity, immune systems, everything is suppressed. After a few weeks, they get really sleep-deprived! They have to wake up and fire up their immune systems for a few hours to take care of any problems that might be around, sleep for about 12 hours, then go back into hibernation.