Spider Habitat Fly Trap

I really liked this design... My son had a large jar of spiders. On occasion he would go on fly hunts to feed the spiders. I had a great idea to improve his habitat and hopefully rid our yard of flies. I printed a new lid for the jar with an inverted funnel (a common fly trap design). I also added a top so he could control when flies could enter. I figured that if we had the right bait the flies would voluntarily feed my son's spiders.

During our test it caught a few flies. Perhaps the flies detected the web because it didn't seem as effective as a normal trap. My son let the spiders go because he didn't like the stinky fly bait in the bottom of the jar. My wife really didn't like any part of it. I was able to dig the parts out of the trash a few times but haven't seen them in months.

An improved design might add some structure to prevent the spiders from spinning webs on the entrance. A removable bottom for cleaning would also be a nice addition.