Fun Fact Friday (#33)

Fun Fact Friday is a meme hosted by Lettora at I’m Booked! If you’d like to join and do your own Fun Fact Friday, just ask! At I’m Booked! Every week we’ll give you five new, fun facts.

This week’s five facts:

1.  Rabbits often sleep with their eyes open

2. The longest time between two twins being born is 87 days apart.

3.  Koala bears aren't bears: They're marsupials.

4.  Rats multiply so quickly that in 18 months, two rats could have over a million descendants.

5.  Hot water is heavier than cold water.