The common wasp is an invasive species in New Zealand. These wasps compete for food with an ant species called Prolasius advenus, which is a native species. Scientists performing an experiment with the insects noticed the wasps doing something unique: picking up ants crawling on food, flying a short distance away, and then dropping the ants. The scientists noticed that while the two species competed for a food source, the ants could be aggressive towards the much larger wasps, trying to bite them or spraying them with formic acid. The researchers think that the wasps might drop the ants, rather than killing them, to touch as little of the formic acid as possible.
Photograph by Julien Grangier, Victoria University of Wellington