We had a small but persistent issue with flies hanging out by our garbage cans so I purchased one of these fly traps with bait.
It worked far too well.
Within a day it had attracted flies from a large surrounding area. The nearly filled jar of flies had a presence I can only describe as "Stephen King-esque" just buzzing with raw malevolence. If you think one large black fly can make quite the noise I invite you to listen to a 1000+ angry flies in a jar.
And while many were certainly capture - an equally abhorrent number were all over the cans and the side of the house. So a mixed experience.
I had the exact same experience it was absolutely disgusting. I attracted all flies from the neighborhood.
I also tried once with an insecticide which also contained a bait, it came in granules and you had to mix with water and spray all over. The floor of my outdoors where full of dead flies.
Best advice I can give: never use any kind of bait. That’s completely BS, you are never going to kill them all. You want flies to go to another place, keep things clean.
My coworker once had one very annoying fly, he was trying to sleep but that fly constantly was landing on him. He turned fan and directed it on bed, so fly couldn't land on him. Now, that little bugger landed just beside of airflow area and just walked to him.
The method I devised to get rid of these large black flies from indoors:
Open a door and simply herd/walk them out by making yourself big. It's surprisingly easy - so much easier than trying to swat them. They seem to instinctively avoid things moving towards them, and because of that they're pretty easy to herd.
Relatedly - if you need to get a light-seeking insect (such as a moth) out of a room, you can just turn off all the lights and open the window. In general, people look at you like a wizard when you exploit the behavior of a creepy-crawly to get it to do what you want. For example you can catch a spider quite easily by placing a drinking glass in front of it and nudging its behind. It will panic-run forward into the glass.
That's when you go out there with a shopvac with a long extension tube; they're already gathered for you. Maybe finish with a long shot of insecticide, then just plug the intake hose into the exhaust port and let it sit for a few days.
It worked far too well.
Within a day it had attracted flies from a large surrounding area. The nearly filled jar of flies had a presence I can only describe as "Stephen King-esque" just buzzing with raw malevolence. If you think one large black fly can make quite the noise I invite you to listen to a 1000+ angry flies in a jar.
And while many were certainly capture - an equally abhorrent number were all over the cans and the side of the house. So a mixed experience.