Sooo yeah. I live on old wooden house. Over 80 years old, and with only traditional ventilation via windows and flap (vent) in the smokestack.

This same vent was trouble earlier on this year. When a lot of small insect (kind of mosquito just Finnish ones) were coming from all the small holes and went's of house. So to be able to went the house and not to suffer from these insects I made hasty cover from old mosquito hat and duck tape. It worked all fine.

However... moment ago I heard weird noise and went to look where it came from and after a while of wondering it came apparent that there was many bats in the vent / mosquito hat combination. I count total four of them. Anyways.. you might like to see this.

Hope you enjoy. :)

https://youtu.be/gXV2m3KNSuc