Bug zappers are shit at killing mosquitoes and excellent at killing beneficial bugs. If you have one running, unplug it.
In 1994, two entomologists at the University of Delaware put six residential zappers in suburban backyards and ran them for ten weeks. Then they counted and identified every single thing that died in them.
13,789 insects total. Only 31 of them were biting insects, like gnats and mosquitoes. Not 31%, 31 total. .2% of the total.
Almost half were non-biting aquatic insects, caddisflies and midges blown in off nearby creeks, which are the base of the food web for fish, bats, swallows and dragonflies.
Another chunk were moths, which pollinate at night and feed the birds and bats in your yard. Roughly 14% were predators that eat pests: ground beetles, parasitic wasps, ladybugs.
The zapper averaged 445 kills per trap per night.
Bug zappers suck at targeting mosquitoes for a simple reason: the female mosquito isn't looking for light. She's tracking the carbon dioxide you exhale, your body heat, the lactic acid on your skin.
She flies past the zapper without it even registering. Every moth in the neighborhood navigates by light, so the device pulls them in from across the yard and kills them.
Notre Dame ran the other half of the test: yards with zappers and yards without had no significant difference in mosquitoes present.
Unplug it. It's doing terrible things for the local environment and nothing beneficial for you.