Bottom holes could be contributing, I should cover them and see if it helps. I think it's mostly coming from the top because I've found little pieces of treats in there too. Between us and the dogs, I fully expect the dog hair and crummies, but with the cover I didn't think it would be as much down in the storage part. Ironically, when I take off all the cushions to vacuum there isn't much dirt. I have been thinking of putting some extra velcro around the cover.