Last weekend, reports of ant swarms came from across Wisconsin including Door County. Friday evening in Sturgeon Bay, homes and vehicles were covered by the creatures. This is a common occurrence in late August and early September. Swarms are caused by special members of an ant colony who develop wings related to diet. Female queens mate during the flight with males from surrounding colonies, collecting enough genetic material to form a new colony once the flight is over. The swarm ends in mere hours, however, isolated colonies may still produce swarms for the next couple of weeks according to UW-Extension Entomologist PJ Liesch.
The swarms last weekend were cornfield ants, an outdoor variety. They won't do harm to homes or start a colony inside. If new swarms pop up, just know they aren't wasps or more dangerous insects. The males die within hours of the flight. Liesch says it is easiest to just let the swarm play out compared to using ant spray.