I keep getting flies in the house (last few days, about 10+ at a time, big green bottle housefly ones). The windows are closed so they must be coming from somewhere inside the house, but I can't find where (have checked all kitchen cupboards, bins etc and nothing obviously festering away). I have no sense of smell since covid so can't follow my nose either. Has anyone else had this and did you find the source? What was it? Need ideas of other things to check! Thank you!