Summary

Flytrap:
So, I was walking my dog and had an idea... It ain't perdy but it works great! I cleared 20+ flies within minutes : ) The model is a bit rough but it works. If you need to shrink the base ring, you might consider maintaining the Z-height so the ribs will fit better. Glue the rib joints.

I've added a better version of the cone without so many edges that could tear the plastic bag.