Do we have rats?
Good morning, I discovered this morning that we have some holes under a bush in the garden and within five feet a hole right near the foundation of our house. Another fifteen or so feet away there's a hole going into a rock wall under the same section of garden. Pictures are attached with a quarter and a 3.5(approx) inch multi-tool for scale. (One of them just has my hand for scale, sorry.) This is all right near a bird feeder. If it's a chipmunk (which we know we have) we'll move the feeder to keep them from burrowing under the foundation. If it's rats, we'll need to call a wildlife removal specialist. Thanks so much!
These do look like rat holes. Rats like to tunnel along foundations (they don't damage the foundation) or other solid surfaces.
Read through the rat section of our website fact sheet: https://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/wildlife/HG90%...
It's not very difficult to trap a rat yourself. (You'd use the same trap for a chipmunk.) You are probably right about the bird feeder being the food source that attracted them. You do not need to feed birds in the summer. Planting more native plants with berries, etc. is also a good way to continue feeding without the pest problems.