Because ants are tiny and they bite and they have 6 legs... They're INSECTS
So... formica is not only the word for ant, but also for beaver? Is that correct? Just wanted to make sure considering I know that ants are insects but beaver is a stretch.
I'm not sure where the beaver definition came from, I wonder if it's a mistake; beaver should be castoro. Formica can be either ant, pronounced stressing the 'i', formìca, or a plastic laminate (https://en.wikipedia.org/wiki/Formica_(plastic) ), pronounced stressing the 'o', fòrmica.
because it is LA formica and UN insetto. the article of insetto doesn't change when the insect (in this case formica) is feminine.