Well, it is a verb and a noun because there is two definition for wriggle.
yes it wriggles in the saltiest of waters, untill it has childern then is obese, but we eat impregnated shrimp, so we are kinda sick human beings. the do give birth really naturally.
because they are dumb.
the same as wiggles. most often it is used as "wriggled free", like to get out of a tight spot, etc.
they use there body to wriggle.