Xenomorph animal kingdom?

what animals though wouldn't be impregnated? there r species the the shape of theyr mouths and heads would make it hard for the face hugger to grab onto no?

Something like an aardvark or an ant eater(those aren't the same thing are they?)

no I believe an aardvark is an armour plated style mammal and the ant eater has that long nose/ mouth and tongue

I think a facehugger would have a hard time with both of them.

A larger animal with a big mouth like a crocodile would be pretty difficult for a facehugger