Article by Chris Buckham
The question relates to Bald-faced hornets, (Dolichovespula maculata). They are a species of wasp and they belong to the group of bees known as yellow-jackets. They are found across the United States and Canada, except for the driest parts of the Great Plains region.
Description: The Bald-faced Hornet is a North American insect that builds a large paper nest to house the social colony. Commonly called the bald-faced hornet (or white-faced hornet), it is not a true hornet. Bald-faced hornets are more closely related to yellow jackets than they are to hornets. These stout-bodied social wasps are black with white markings on the front of the head and the tip of the abdomen. The face in primarily white with dark eyes. Front wings of hornets and other Vespidae are folded lengthwise when at rest. The large antennae are conspicuous. Due to their size, shape and coloration these wasps are sometimes mistaken for bees.
Bald-faced Hornets are known for their large ball-shaped paper nest, which they build in the spring for raising their young. These nests can sometimes reach 3 feet tall.
Diet: Soft-bodied insects including caterpillars and aphids are popular food items. They harvest nectar (carbohydrates) and pollen (protein) from flowering plants. They are attracted to meats just like the yellowjackets.
Behavior: Bald-faced Hornets are social insects that live in large colonies. The queen bee, drones and worker bees all have specific tasks to help support the colony. The queen lays hundreds of eggs. The male drones' main function is to be ready to fertilize a receptive queen. Workers do all the different tasks needed to operate and maintain the nest.
In late summer, bald-faced hornets visit flowers to collect nectar, so they are known as minor pollinators.
Ref: http://naturemappingfoundation.org/natmap/facts/bald-faced_hornet_712.html