Summary

Fly trap. An idea as old as the world. I just wanted to give it some color.
I'm not sure what attracts flies most effectively but my uncle Google has many theories about this.
Instruction:
The trap is adapted to a bottle with an outer diameter of 74mm.
You can scale it
I cut the middle part of the bottle in two places with a glass knife and then put it in hot water. After a while, the bottle evenly burst in the cut spots giving a cylinder.
The edges were sanded with sandpaper to better fit the parts attached to the cylinder.

You can find more of my projects at:
https://cults3d.com/en/users/ombre-gringo/creations

Thanks, enjoy!