Early in the spring and summer, protein in the form of live prey is the usual diet consisting of flies, other yellow jackets and many other types of insects. Some nests are so full of yellow jacket remains that the inside has a yellowish cast to it. As the season progresses and there are fewer larvae to feed, the workers will take nectar and other forms of carbohydrates.
Not an important vector of human disease.
Bald faced hornets have a smooth stinger and hence unlike the bees, they can sting more than once and in some cases repeatedly injecting a venomous liquid under the skin of the victim. Though the venom from these wasps may not be poisonous for the commoner, it can potentially turn fatal to those who are allergic to bald faced hornet stings. If you spot a bald faced hornet nest near to an area where there is high human activity, then it is recommended that all measures are taken to remove it at once.