I've been feeding them on and off for a while, is there still a chance they pop out of the bubble and you get to keep them? It hasn't happened to me in ages and I'm wondering if the feature got removed!

Yes it still can happen but the chances are slim

Thank you very much for the answer, guess I'll just keep feeding those poor lil' things! ^^

Ya ^^ and np :)

I just got one of the minions a couple days ago, so it does happen, just rarely.