The difference between antlers and horns is that antlers are shed each year and are made of bone while horns are kept for life and are made of living tissue and bone with a sheath that is very similar to human finger nails.
10
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Cymothoa exigua is a type of parasite that enters through fish's gills, eats their tongue, and then replaces it.
6
Mosquitoes prefer certain blood types, and people with the “O” blood type are more likely to get bitten.
12
A cat rubs against people not only to be affectionate but also to mark out its territory with scent glands around its face. The tail area and paws also carry the cat's scent.
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