Are Stink Bugs Poisonous?

Even if you’ve never seen a stink bug, you may well have smelled one. These shield-shaped bugs come in many different varieties, but all emit a nasty odor as their main defense mechanism against predators.

Stink bugs are common across North America, but they aren’t poisonous to humans or animals; nor do they bite, sting or spread diseases. However, they can cause some serious problems in your garden and are not to be mistaken for the assassin bug, which can transmit potentially life-threatening infections.

What are stink bugs?

Stink bugs are insects that are primarily known for the cocktail of foul-smelling chemicals they release when threatened or squished. There are several species of stink bug native to North America, but the brown marmorated stink bug (BMSB) is one of the most problematic.

These invasive species first arrived in the United States back in the mid-1990s, when they hitch-hiked their way over on shipping containers bound from Asia.

Since then, these bad-smelling bugs have invaded many states across the country and are proving a real nuisance. BMSB can be recognized by their shield-shaped bodies, their mottled brown and cream coloring and (of course) their terrible odor.

Are stink bugs harmful to humans?

Stink bugs do not bite, sting or spread diseases and, most of the time, are not dangerous for humans.

However, some people are sensitive to the malodorous compounds they release and may experience an allergic reaction is they accidentally handle or squash one of the bugs.

Potential symptoms of an allergic response to stink bugs may include:

  • Itching or watering eyes
  • A runny nose
  • Dermatitis (a skin rash)

Are stink bugs harmful to pets?

They may not harm humans, but are stink bugs poisonous to your pets?

You can’t stop cats and dogs from sniffing, swatting or chasing bugs but, thankfully, stink bugs are generally not harmful to pets.

However, the chemicals they release when they feel threatened could irritate the eyes or nose of your pet and cause excessive drooling. Eating bugs may also irritate your pet’s gastrointestinal tract, which can lead to vomiting and/or diarrhea.

Luckily, usually, these symptoms are not serious and clear up by themselves within a day or two. If they persist for longer than this, you should take your dog or cat for assessment by a vet.

Why do people think stink bugs are poisonous?

Stink bugs are not poisonous, they don’t bite or sting and they don’t carry diseases, so why do they have such a bad reputation?

Did you know?

The main reason why people think stink bugs are poisonous is that they look a lot like the assassin bug.

These insects (which are more commonly referred to as kissing bugs) do bite, and they just so happen to closely resemble stink bugs.

Kissing bugs are so-called because they tend to bite their victims on the face while they are sleeping. When they bite, they inject some of their saliva into the wound, which acts as a local anesthetic.

Usually, a bite from a kissing bug will cause nothing more than itching, redness, and swelling though, sometimes, they can result in a severe allergic reaction.

Some kissing bugs also carry the Trypanosoma cruzi parasite in their feces, which causes Chagas disease. This parasite can be transmitted to people if kissing bug poop is accidentally rubbed into the bite wound. Chagas disease is a serious and potentially life-threatening condition but, fortunately, your chances of catching it are low even if you are bitten by a parasite-carrying kissing bug.

So, how can you tell a stink bug from a kissing bug?

The best way to tell these two apart is to look for red, orange or yellow markings on their bodies. Kissing bugs have them but stink bugs don’t.

What’s the problem with stink bugs?

Stink bugs can’t make you sick, but they may have a detrimental effect on the health of your garden.

Stink bugs are a significant crop pest and are known to infest a wide range of plants including tomatoes, beans, peppers, and sweet corn, though their preferred hosts appear to be fruit trees.

The BMSB often overwinters indoors to escape the harsh, outdoor temperatures, emerging in spring to lay their eggs in the blossoms of fruit trees. The new BMSB nymphs while away the summer feeding on the fruits and seed pods of the tree before molting into adults in late summer.


The damage caused by the nymphs usually appears as discolored or sunken spots on the skin of affected fruits. In the case of apples, the feeding on the nymphs creates characteristic brown, ‘corky’ spots under the skin of the fruit.

How can you prevent stink bugs?

Stink bugs are probably most problematic when they enter homes, as the pungent smell they give off can take a while to dissipate in more closed-off spaces.

If you live in an area with a large summer stink bug population, take the following measures to prevent them from coming indoors:

Seal off all possible entry points

Perform a thorough inspection of your house and seal off all possible stink bug entry points with caulk. These can be gaps around windows, doors or pipes, or cracks in the exterior of your house.

Install screens and door sweeps

It may not be possible to close off every little crack around your windows and doors, but installing screens, sweeps and draft excluders can keep all kinds of unwanted bugs out.

De-clutter your yard

Make it more difficult for stink bugs to get near your house may removing any nearby outdoor harborage sites. This can include shrubs, tall grasses, pot plants, leaf piles, and other general debris near the foundation of your house.


Stink bugs are not poisonous to humans or pets, and they don’t bite, sting or spread diseases. Unfortunately, they are still a nuisance insect, mainly because of the obnoxious-smelling compounds they release when threatened. This defense mechanism against predators can also be triggered when the bugs are accidentally handled or squished and can be especially overwhelming in enclosed spaces (like indoors).

Stink bugs can also be prolific plant pests, and none more so than the brown marmorated stink bug (BMSB). This voracious fruit-feeder is actually native to parts of Asia but was unintentionally introduced to the US sometime in the 1990s. Since then, this stinky insect has invaded states across the country and is responsible for widespread damage to a variety of crop plants.

Submit a comment

Your email address will not be published*