What's the Difference Between a Hornet and a Wasp?

"Hornets are just a kind of wasp," Jason Gibbs, assistant professor of entomology at the University of Manitoba said in a 2019 email interview. "Wasp is a very broad term that covers many different species with different lifestyles."

There are more than 100,000 wasp species on Earth, each a testament to the startling diversity in these winged bugs. Wasps are found in every part of the world except polar areas. It's usually easy to identify them, as they most often have black and yellow stripes, a well-defined and narrow waist, and tapered abdomens.

Hornets tend to be a little chubbier and larger than their svelte wasp brethren, and some species forego common yellow and black striping for white and black markings. Their increased size means they also carry a substantial load of venom, so in some cases hornet insects are more dangerous than other kinds of wasps. However, certain wasps are considered the most aggressive stinging insects.

Fortunately, if you leave hornets and wasps alone, they generally want nothing to do with you.

The main difference between a hornet and wasp nest is the size and structure. Wasps and hornets both build paper nests from chewed wood fibers and saliva.

A hornet's nest will likely be teardrop shaped and about the size of a basketball. It will also have hexagonal combs and one entrance.

A wasp's nest will usually be grayish-brown and spherical in shape. They start off very small but usually grow to about the size of a football — or larger.

You'll likely find both wasp nests hanging from many horizontal surfaces, including roof eaves, garage ceilings and other places. Hornets prefer to build their nests in tree branches and shrubs, but you might also find them in the eaves of your house, in attics or in crawl spaces. Some hornets, like the giant European hornet, also burrow into the ground to build nests.

Wasps, like honey bees, are incredibly important pollinators, helping keep plant life and agricultural crops healthy. They tend to chow down on caterpillars and harmful flies, too, making them beneficial to humans. That's one reason some places, like Germany, ban people from disturbing them or their nests.

"Hornets are predators [and] scavengers, as are most wasps," says Gibbs. And by scavenger, he means wasps exhibit a voracious affinity for sugary foods and drinks. Wasps are the pest insects that make themselves unwelcome guests at outdoor gatherings like picnics or sporting events.

Furthermore, wasps also love the sweet deliciousness of rotting, fermented fruit that falls to the ground in autumn. They'll gorge themselves to the point that they'll become drunkenly aggressive, sometimes chasing pets or people trying to sting repeatedly if they feel annoyed or threatened.

As their natural food sources continue to dwindle in the fall, wasps may become even bolder, and sting multiple times, so limit their access to human foods. That keeps you — and the wasps — safe from harm.

While hornets may eat fruit or picnic food, they're much more likely to feed on insects, like crickets and grasshoppers.

Wasps are broadly divided into two categories: social and solitary species. Eusocial wasps include species such as paper wasps, yellow jackets, and yes, hornets. Eusocialjust means they're very social and live in groups with a queen, cooperatively caring for their young.

Most wasp species are considered solitary wasps. Females live alone and reproduce using some notable techniques, including laying eggs on other insects (like spiders), which they paralyze and hold hostage in their own nests. Eventually, they kill the hosts, which serve as food for wasp larvae.

Social wasps, on the other hand, live in large colonies — in populations often exceeding 100 members — with an egg-laying queen, as well as workers that do not reproduce.

"Wasps and bees have evolved social behavior more often than any other group of animal, and interestingly have lost it many times too," says Gibbs. "Eusocial behavior (basically overlapping generations with reproductive division labor, i.e. queens and workers) has evolved multiple times in the animal kingdom."

This behavior has also been recognized in sweat bees, Gibbs' area of expertise. "Sweat bees are particularly interesting for studies of social evolution because they are so many back-and-forths in the evolutionary tree. In fact, you can have eusocial and solitary nests within the same species," he says. "It's incredibly complex and interesting and, wonderfully, all of this is going on under our noses."

Yellow jackets are yet another type of social wasp. They're smaller and build underground nests that may feature hundreds of wasps. Some people mistake these pint-sized wasps (which have bodies around half an inch long) for bees.

As their ground nests expand, the soil becomes looser and creates a sinkhole. If you're unlucky enough to step into one of these sinkholes, you may find yourself at the mercy of hundreds of angry stinging insects.

Another example of a eusocial wasp is the bald faced hornet. Bald faced hornets have ivory-white markings on the face and are very defensive around their nest. The workers also will sting repeatedly if they feel threatened.

Solitary wasps, like mud daubers, rarely sting. That's true even if you disturb their nests. They don't attempt to defend them.

Eusocial wasps and hornets, on the other hand, can be extremely aggressive if you threaten them or their nests. Often, they'll swarm intruders and sting multiple times. Swatting at wasps is, shall we say, a bad idea. Doing so triggers the insect to release pheromones alerting other wasps to a threat (you) and that it's time to attack.

Even one wasp sting can be very painful. Multiple stings might cause serious harm, particularly to anyone who's allergic to the venom. And in worst-case scenarios, wasps might sting dozens or hundreds of times, an act that can kill even strong, healthy people who aren't allergic to the venom.

The best strategy to prevent a wasp sting is to keep food covered if outside, particularly sugary drinks, so you don't attract wasps. If one wasp flies near you, remain calm; it will probably just fly off. If a swarm comes near you, run away in a straight line without waving your arms.