We came back from being out of town for 5 days and found what I guess are fruit flies all over our kitchen!! We didn't leave any food out and emptyed the trash before we left so I don't know what attracted them. I've heard that vinegar or basil can get rid of them but I tried those and it didn't help. They're driving us crazy! What can we use that is nontoxic to get rid of them? TIA.