Actual Size: 1/2″

Characteristics: Bright yellow color.


  • Yellow jackets are moderately aggressive.
  • Their nests are not exposed and typically found in the ground or in a tree.
  • High populations of yellow jackets are common in summer.
  • They will seek out fruit and sugar during the summer months; yellow jackets are also attracted to bright colors and perfume.

Every creature on the planet has a role to play in the survival of their ecosystem. This even goes for pests we hate having around – especially those with an annoying bite or painful sting. Insects like bees and wasps do a lot for the environment, whether they’re pollinating, scavenging, or acting as food for other animals.

During the warmer months in states like San Francisco, you’re more likely to come across stinging insects. While they’re not normally aggressive, this doesn’t mean you won’t be stung. Before you go buy the largest can of insecticide you can find, it’s important to know what you’re dealing with and the potential environmental impact your decisions could have.

Often mistaken for bees, due to their yellow-and-black coloring, yellow jackets are actually wasps. At about 1 1/2 inches long, they triple the average honey bee in length. Although the end of the warm-weather months means larvae production stops and males die off after mating, the yellowjacket is at its most active during the late summer in Wisconsin.

Yellowjacket Fall Frenzy

Food becomes scarce as flowers are no longer in bloom. Like us, wasps get cranky when they’re hungry. They become more aggressive, stinging with even the slightest provocation. In their desperate search for food, they explore every possibility — including the folds of human skin. The yellowjacket will sting, often multiple times, when a victim bends a limb and squeezes the insect at the crook of an elbow or behind a knee. The wasp’s sting is very painful, not to mention dangerous to those with sensitivities. The anaphylactic shock from bee and wasp stings kills as many as 50 people in the U.S. annually.

Yellowjacket Nests

Of the two varieties of yellow jackets in the state, the German yellowjacket prefers to construct its nests inside building walls. Yellowjackets’ nests are at their largest at summer’s end and can also be found in trees, shrubs, or underground. Indoor nests, which are especially tricky to remove, allow these wasps to remain active through the end of the year. And while yellow jackets don’t reuse their nests, instead of building new ones in the spring, it’s important to get rid of them. Old, abandoned yellow jacket nests attract other kinds of pests.

Wasps in San Francisco

Bees and wasps can sometimes be confused with each other, but there are some major differences between the two. Only a small number of wasps act as pollinators; the majority are scavengers and predators of agricultural pests like beetles, grubs, and aphids. Some farmers even introduce wild wasps into their fields as a natural form of pest control!

However, because of their predatory instincts, wasps tend to be more aggressive than their bee brethren. Hornets, yellow jackets, and paper wasps are three common pests in San Francisco, and will aggressively defend their nests if they feel threatened. Their nesting habits are slightly different from each other:

  • Hornets can form large nests the size of a softball
  • Paper wasps typically form a visible nest that looks like an upside-down umbrella, typically under eaves and awnings
  • Yellowjacket nests are hidden and can be found both in the ground and high above where the siding meets the eaves

Mud dauber wasps, on the other hand, are more docile. True to their name, they make nests out of the mud. These mud nests often look like organ pipes and contain rations of captured spiders for their young. Unlike bees, which can only sting once, wasps have reinforced stingers containing venom that allow them to inflict multiple, painful stings that can cause severe allergic reactions – and in some cases anaphylactic shock, which can be fatal.

What You Can Do

In most cases, it’s best to avoid bees and wasps entirely, as they are normally not a danger to humans. However, when their nests are in close proximity to us, they are more likely to perceive a threat and defend their nest at all costs. Additionally, in the late summer months, some bees and wasps become more aggressive in seeking out food like sugar and fruit, which can bring them into contact with you and your family. If you decide to use pesticide or chemical sprays, keep in mind they can be extremely poisonous and should never be used indoors or near other people.

The Hitmen Solution

Although most insects are environmentally beneficial, it can be difficult to coexist peacefully when they invade your personal space. Bees and wasps can be dangerous to people and often destructive to homes and other structures.

Hitmen will safely and carefully eliminate bees or wasps and their nests from your home or property. Exposed nests may be removed on the day of service depending on the activity and size of the nest. In other cases, we’ll come back on a day when it is safer to remove the nests. In addition, we will create a full report describing the treatment and how you can protect your home from further infestation.

What happens if bee or wasp nests form again? Don’t worry. Our year-round pest control program, which covers common San Francisco pests, will ensure your home and property are protected throughout the entire year.

To schedule a stinging pest removal service, contact us today!