Why can't 'eating' be 'mangent'?
It's because we don't say 'manger son déjeuner' in French but 'prendre son déjeuner'.
Or isn't there a variation of this because déjeuner means to eat lunch. . . Might i be able to skip prennent?
You may, by using the verb "déjeunent".
I'm so disappointed. The first time Duolingo showed me "coccinelle" it was the British "ladybird", which is also how we say it in Australia. Since then it's been the American "ladybug".
"Ladybird" is an accepted variant but may not necessarily be shown in the version with sliding word-tiles.