Ζουζούνι = bug; the word is used in informal contexts the way bug is used informally in English. (There is a formal definition of bugs as a very specific group of insects - these are the "true bugs" in English.)
Έντομο = insect; a clear zoological classification is implied here, but the word can be used in both formal and informal situations.
I'm not sure if this is the place where I should post this, but I think this section is throwing too much NEW words at us instead of focusing in just five or six, which is the way the "animal topic" is covered in other courses. The word just won't stick in our heads if we see them just once, guys!
But marcelo, you can choose which ones are the most interesting for you.
The ones I have missed here are:
donkey, rabbit goat - all the village ones, which I still don't know. Sign language (for ears or beard) actually works but I really should learn the words as I do sometimes misunderstand rabbit for donkey, because they both have long ears. :-)
I don't know if this is a good place to post this: the hints and tips offer little help for this part.
The list of animals provided in hints & tips doesn't correspond to the animals covered in exercises, meaning that it's not possible to review words like καμηλοπάρδαλη and καβούρι outside the exercise.