Hi;
I have problems with squirells digging - I use a piece of chicken wire cut to size to put over top of my planters. Cut opening the size of stem/trunk, or just put over & let plants grow thru the openings. Layers of mid-size pebbles/stones/rocks help too...

I would agree... cats, also, like to dig in pots and use them as personal restrooms, so if you have wandering neighborhood cats, chicken wire sounds like a good idea. The plants, depending on what type they are, should grow through without any problems. It's not that difficult to cut the wire, anyway, should you eventually need to remove it.

I always have some digging from the squirrels, but I can deal with that. I cannot use any fish emulsions or blood meal, at all or the raccoons will dig everything out of the containers. Al

I had a chipmunk that was digging in my containers. I had some scrap bird netting and I used that the wrap the container and the base of the plant. That seemed to have work. Also, I second putting rocks in the container next to already growing plants.

Mice and other small rodents can present issues, as well. I've had many a plant dug up and disturbed by mice. I've experienced a lot less issues since I changed to using a more gritty type of medium, but I think any kind of wire or netting will discourage any digging.

I think it also helps that I stick with chemical feeding for container growing, and save any organic fertilizers for the garden. I think Calistoga Al is right... small rodent type animals and pests like raccoons are attracted by things like blood meal, etc...