which are apparently the latest 'Be Kind To Gaia' thing("They give us eggs!" etc.) and what happens with uppie-enviroweenie types when the hens get old. I've known a few people who kept a few and considered the eggs a bonus: the big reason to have them was bugs. Any bugs. The chickens kept everything from grasshoppers to ticks down. Mice too, as chickens will eat ANYTHING.
In the comments Marja mentioned having had the 'piglets are cute' scared out of her as a kid by adult pigs, which reminded me of a time I was helping Dad at a farm where he was working part-time; he and the farmer both pointed out a big sow and very specifically told me to stay the hell away from her AND the fence anywhere near her, as she was a bad-tempered bitch(they put it more politely) and WOULD try to take a bite out of you. The farmer said he had to be careful around her, worst when she had a litter but she was nasty the rest of the time, too. A little later I got a look at her teeth, and staying away was not a problem.
Was about a year after that in Vo-Ag that the teacher gave us a lecture about pigs that included "Some are nasty, and they will get you if they can." Reinforced the lesson: just because something is domesticated doesn't mean it won't kill you.