How do non-violent humans deal with, say, mice or ants getting into the food supply?

A) For mice: spread a little 20-Mule team Borax around the hole. They hate the stuff and will leave.

B) For ants: Find their entry point. Drop a few drops of Coca-Cola around it. They slurp it up, get drunk (get a magnifying glass and watch. It's a hoot when they get snockered and start trying to walk on 6 feet going in as many different directions.) Anyway, after they sober up, they stay away from that spot.

Yea, I know it sucks but you're going to have to pitch it. I wouldn't worry about buying canned food though unless you want to. It's much more expensive especially if you have a big dog. You're obviously going to have to deal with the ants anyway. Get some ant traps and stuff. I also recommend those Bug Plug things. (Ultrasonic sound or something you plug into the wall) They don't bother other animals, but they scare bugs away or something. They REALLY worked at my house for sure I noticed a huge difference in the amount of spiders, centipedes and ants I've seen since. They were hard to find, but I got mine at Target. Once the ants are all gone, I would continue buying the same food, but just buy a big Tupperware container and dump everything in there to keep it fresh and clean. That's what I do. It also makes it easier to scoop out and store. Good luck!

Set up a ramp (piece of cardboard, yardstick, whatever) leading to a trashcan. Atop the ramp, place a tp tube (or something similar, say, a hot pocket crisping sleeve) with peanut butter in it. Set the sleeve/tube on the top of the ramp so that if it is unbalanced, it will fall in the can. (Make sure the peanut butter is toward the can.) Ensure that you release any mice as far away from your home as you can get them feasibly (at least a mile or two) so they do not come back.

As for the ants, spray bleach or degreaser on the floor/surface. They won't cross it. Then again, I wouldn't cross a moat of something that would boil me alive, either.

Funny you should mention this, I was awakened last night to find a cockroach the size of a German Shepard crawling across my floor. First thing this morning I went to Home Depot and bought $50 worth of a variety of roach killers. I left my house, with Armageddon reigning down on the bastards. Hopefully they will all be in heaven when I return.

Is it morally unacceptable for a cat to do it?

With the ants, keeping food in plastic and cleaning with ammonia is enough.

I hope you're wearing a mask when you breathe....don't want to kill microbes by inhaling them.

I'm glad evolution made me an omnivore and the gods made me Wiccan.

I don't take joy in killing animals, either. But I have recently had a mouse in my home and had to kill it. They are dirty and disease infested, and I would rather look out for the safety of the people in the home than not kill the mouse. If you keep avoiding the unpleasantness, someone may get sick...maybe call a professional.

You had better get an exterminator and then clean and sanitize where it came in and might have traveled. It has no soul and so you are not sinning if you have it exterminated.

Your health and soul are more important than some mouse that wondered into your home from the outside, They bring diseases; did you not know this?

Starve

Here is a little deeper one for you... when you wash your hands you are killing germs and bacteria... I would hate to smell you in a few months. Same thing applies when you cook your food...

Just a ridiculous point to show how naive your ideals are.

Try keeping your food in containers with lids.

Enjoy the diseases from not killing germs.