We had fruit flies in an OR once. A colleague of mine did a ton of digging to find the source. Turns out the fruit flies were breeding in the basement laundry

We had fruit flies in an OR once. A colleague of mine did a ton of digging to find the source. Turns out the fruit flies were breeding in the basement laundry holding area where a staff member was pouring out dextrose and saline into a floor drain. There was a service elevator near the drain that lead up to the 9th floor where the ORs were. The flies were taking the elevator up then flying to 15ft or so into the OR.