Do Bumblebees Sting? Why They Rarely Do and the Real Risk

Which bumblebees can sting?

A bee’s sting is a modified ovipositor, the tube that other insects use to lay eggs. That is why only female bumblebees have one. Queens and workers of nesting species such as the buff-tailed bumblebee all carry a sting with a venom gland at its base.

Males, which appear in summer and autumn, have no sting. They are often the bumblebees seen sleeping on flowers or resting on garden walls late in the season, and they are completely harmless. Male bumblebees can often be recognized by their longer antennae and, in some species, yellow facial hair, but telling the sexes apart takes practice.

Cuckoo bumblebees, which take over the nests of other bumblebees instead of raising their own workers, also have stinging females. They use their stings and tough bodies to fight their way into host colonies, but they ignore people unless handled.

Why do bumblebees rarely sting?

A bumblebee visiting flowers has no reason to sting. It is away from its nest, gathering nectar and pollen, and its usual response to a large animal is simply to fly off. Stinging uses venom that takes time and food to replace, so bees keep it for real emergencies.

Bumblebee colonies are also small. A nest usually holds from a few dozen to a few hundred bees and only a few days’ worth of stored nectar, while a honey bee hive holds tens of thousands of bees and many kilograms of honey worth defending. Bumblebee nests do attract raiders, such as badgers digging for the brood, and that is when workers sting in earnest.

Most people who are stung by a bumblebee have accidentally:

• grabbed or squeezed a bee, for example while picking flowers or swatting it
• stepped on one barefoot, especially on a lawn full of clover
• trapped one in clothing, a shoe or a towel
• disturbed a nest while mowing, digging, moving a compost heap or cleaning out a bird box

Warning signs before a sting

Bumblebees usually warn before they sting. A disturbed bee often lifts one middle leg toward the threat, which bumblebee experts describe as a clear signal to back away. If the threat continues, the bee may buzz loudly or roll onto its back, pointing the tip of its abdomen and sting upward.

These displays mean “go away”, not that an attack is coming. Stepping back and leaving the bee alone almost always ends the encounter. Bees near the entrance of a nest are more defensive, and species that nest above ground, such as the tree bumblebee, which often uses bird boxes, may fly at people who come very close.

Can a bumblebee sting more than once?

Yes. A bumblebee’s sting is smooth rather than heavily barbed, so it slides out of skin easily and the bee can sting again. A worker honey bee is different: its barbed sting lodges in elastic skin and tears away with the venom sac, killing the bee. That difference is explained in do bees die after stinging?

Wasps and hornets also have smooth stings and can sting repeatedly; see can a wasp sting more than once? For other differences between these insects, see bee vs wasp.

What does a bumblebee sting feel like?

A bumblebee sting causes a sudden, sharp, burning pain, followed by redness and swelling around the spot. For most people the pain fades within minutes to hours, and the swelling settles over a day or two. The bee does not leave its sting in the skin.

Entomologist Justin Schmidt, who rated the pain of many insect stings he experienced, ranked bumblebee and honey bee stings at a similar, moderate level, well below the most painful stings of tropical wasps and ants.

How dangerous is a bumblebee sting?

For the great majority of people, a bumblebee sting is painful but harmless. The real risk is for the small minority of people who are allergic to insect venom. Bumblebee venom shares some components with honey bee venom, so people allergic to honey bee stings can also react to bumblebees. People who work every day with commercial bumblebee colonies in greenhouses are the group most likely to become allergic to bumblebee venom itself.

Signs of a severe allergic reaction include difficulty breathing, swelling of the face, lips or throat, a widespread rash, dizziness or collapse, usually within minutes of the sting. Anyone with these symptoms needs emergency medical help immediately: call 911 in the US, 112 in the EU or 999 in the UK.

Myths about bumblebee stings

“Bumblebees can’t sting.” Many people grew up believing this, perhaps because bumblebees are so gentle. Female bumblebees can sting, although they seldom do.

“Bumblebees die after stinging.” That is true only of worker honey bees. Bumblebees survive and can sting again.

“A bumblebee buzzing near you is about to attack.” Bumblebees buzz whenever they fly. A bee circling close to you is usually investigating a bright color or a scent, or simply passing by on its way between flowers.