Put some hay or grass clippings in it. Since it's supposed to attract mosquitoes, you probably don't want it really close to where people congregate. I have 4: 3 around the perimeter of my yard, & 1 in a low spot where the mosquitoes usually seem to be the worst.
I'm sorry, but I love killing mosquitoes. I guess that makes me some sort of sadist. But they annoy me & spread disease. Fuck them. 😂