This is a European Hornet, and they are often encountered in late summer and autumn since nest populations of social wasps are at their largest this time of year. Individual nests are not re-used from year to year, and members of an existing nest will die out soon and only young queens will remain, having dispersed and sought-out sheltered overwintering sites like under a log or in a rock crevice. Individual hornets noticeably larger in size than others are probably the recently-hatched young queens which will start their own nests (not always successfully) by themselves next year.

This hornet is unique for its activity during both and night, and like many night-flying insects, can be readily drawn to outdoor night lighting, both because of the light source itself as well as for the other insects it attracts, which they can hunt and bring back to the nest for their larvae. Turning off a porch light or lamp post may help keep them away from windows, assuming blinds or curtains don't leak too much light.

Adult wasps only consume liquid sugary diets, and will be drawn to flower nectar, fruit juices, and tree sap, among other substances. European Hornets sometimes chew into the bark of plants like lilac, viburnum, and birch in order to generate sap flow that they can then feed off of, but this generally doesn't cause the plant serious damage.

Miri