Adult lice, for example, are about as large as a sesame seed, while baby lice, or nymphs, are a fraction that size. Lice are well camouflaged too, matching the color of the hair around them.

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First thing's first. Sea lice aren't lice at all. They're tiny baby jellyfish, so small you can't even see them -- about the size of a grain of pepper. And just like their grownup counterparts ...