Peppermint oil and water
Here are a few videos for you to take a look at!
Fly strips may not look good, but they are really effective at tripping flies.
Dishwashing liquid and vinegar
Hi Rosie: Here are a couple of sites that may help:
This one is goofy, but it might work:
This one is something to build:
This one tells about drain and other flies, if you scroll down a bit:
Thank you guys I'll check them all out ☺
Hi Rosie, this may give you some ideas