It’s definitely squirrels and rats looking for food, but yeah there’s not much you can do unfortunately. If you could get your neighbors to put their trash in a can with a lid, or put their trash out in the morning, your problem would be solved.

I know it’s annoying, but maybe making a sign or leave a note for your neighbors to see that clues them into the fact that it’s animals who are tearing open the bags to get their food scraps. I know that they should know better, but I wouldn’t be surprised if they didn’t ever think about it. Maybe hoping that they would do something different after finding out is naive, but I doubt they wanna be stepping over tons of trash outside their own building every day. Hopefully.