How Many Wasps Could Be in a Nest I'm Attempting to Eliminate?

A small, early-season paper-wasp nest — the kind found under an eave before workers have fully built up — can be a modest colony of a few dozen individuals or fewer. By contrast, Cornell IPM notes that the eastern yellowjacket (Vespula maculifrons), one of the yellowjackets common across the Northeast and New Hampshire, can build colonies of roughly 2,000 to 3,000 workers, and other extension figures describe some nests exceeding 10,000 cells in a season. In southern New Hampshire that maximum lands in late summer and early fall, just before the first sustained hard freeze — around Manchester the local average first 32°F freeze is near October 19 — so a nest found in September is far more likely to be near peak size than one found in June. Bald-faced hornet and European hornet colonies generally fall somewhere in between, typically in the hundreds of workers by late summer.

Colony size is the single biggest driver of how bad a disturbance could get, because a defended nest recruits nestmates through an alarm response rather than relying on one or two individuals to respond. A small colony has a limited number of wasps that could possibly respond to a disturbance; a large one can mount a coordinated response involving hundreds of workers within seconds. That's a meaningfully different physical situation, even though both might look like "a wasp nest" from a few feet away.

An exposed paper-wasp nest at least shows its comb, which gives some rough sense of scale. A ground, wall-void, or attic nest shows none of that — the entrance hole looks the same whether a few dozen or a few thousand wasps are behind it, and traffic level at any given moment doesn't reliably scale with total colony size. That uncertainty is itself one of the reasons concealed nests are treated more cautiously on this hub than exposed ones, independent of any other factor.