My players keep eating the NPCs

Hey everyone! I’m a new DM and I recently started running a D&D campaign for a group of friends. Everything has been going pretty well so far but I’ve noticed a weird habit that my players have developed. They are eating my NPCs.

So far they’ve eaten 3 of them and I think they’re planning to eat at least 2 more. I’ve never DMed a campaign before and I’ve only been a player in one other campaign. I’m just wondering if this is normal? Has anyone else had to deal with this kind of situation before?