i use a fly trap bag from amazon

RESCUE! Outdoor Disposable Hanging Fly Trap - 2 Pack https://www.amazon.com/dp/B07BTY75CV/ref=cm_sw_r_cp_apip_wtgYmkfTxgKQ8

These Rescue Fly Traps are amazing. We had a huge fly problem outside last year. These helped last summer and so far this year we have only seen a few flies. We still keep them outside and they are still catching lots of flies. They smell pretty bad, so place them away from your house.

RESCUE! Outdoor Disposable Fly Trap, Green, 2 Pack https://www.amazon.com/dp/B07BTY75CV/ref=cm_sw_r_cp_api_i_4MZSRWHT55HYH3E5BBNJ?_encoding=UTF8&psc=1