How can I prevent mosquitoes in humidity trays?

[nynighthawk]

Hi folks,

Well, it's skeeter time in New York City.

I've already seen the little critters and I'm wondering what y'all do to avoid them getting into humidity trays and breeding in the water?

I'm using broken terracotta potsherds in the trays and the water is usually about 1/4-1/2 inch deep. Plenty deep for mosquitoes to breed in. It only takes one to start a population boom.

I cruised the earlier conversation threads and someone suggested "mosquito bits" as a remedy for fungus gnats.

What do you all do to avoid mosquitoes, though?

Any suggestions greatly appreciated. I hate those $)(@% critters. They love me, though...not in a good way. LOL

Thanks!