Christmas Island has bridges for crabs to stop them getting run over during the mass migration.
9
Dogs have been man's pet for over 14,000 years.
224
When dragonflies mate, their tails form a love heart.
22
Dolphins can rapidly heal from extreme injuries, such as shark bites, and regenerate their original body shape.
19
Sifrhippus was a species of horse about the size of an average duck and roamed North America 56 million years ago.
2