How long have these stores been there? Are they old buildings and the store has been there forever?
I can tell you from my grocery days, old supermarkets are dirty. Not necessarily because of any fault of the employees or management or the company, but that’s just the way they get. When you’ve got a building that’s packed with food and open doorways everywhere, sooner or later it’s going to get mice and insects and shit. It’s inevitable, no matter how clean you try to keep it or how vigilant you are about countermeasures for pests. The older the building, the longer the store has been there, the worse the problem is going to be.
I worked in a relatively new store, been open about a decade and we kept it pretty clean, but there were definitely mice and roaches and shit all over the back room and, presumably, underneath and inside the shelves. Every now and then I would get sent into a store down in the city to help solve their backstock issues, and one particular store that had been there for like 60 years was just the most horribly dirty place ever. I saw the nightstockers all had rubber mallets hanging off of their belts and I asked them why. They took me into the back room to a pile of backstock piled against a wall. “Pull out a box.” So I did, and a dozen little brown mice came rushing out and the guy proceeded to smash as many as he could with the mallet.
I know that’s gross and not something you want to know or think about, but that shit is unavoidable. There’s really nothing the store can do about it save for tearing the place down and building an entirely new store in its place, but eventually they’re just going to come back. That’s why I scrub the shit out of all the produce I buy at the supermarket(I usually try to go to the farmer’s market) and always inspect the things I pull off the shelves.