Bumble bees (Bombus spp.) are widely recognized as powerful and fuzzy pollinators. While their distinctive black and yellow coloration serves as a universal warning signal, and worker bees are equipped with a stinger, these defenses do not make them immune to predation. The threats they face are diverse, ranging from large mammals that destroy their entire home to highly specialized insects that ambush them while foraging.
Mammalian Predators That Target Nests
Mammalian predators typically focus on the bumble bee’s nest, which represents a concentrated source of protein and carbohydrates. Animals such as badgers and skunks have evolved methods to access these underground or hidden colonies despite the defensive swarm. Badgers, with their powerful claws and muscled forelimbs, are known to simply dig up the entire nest structure to consume the brood and provisions within.
Skunks employ a different, more cautious strategy by approaching the nest entrance at night and scratching the ground to provoke the guard bees. As the defensive bees emerge, the skunk rapidly scoops them up and chews them to extract the soft body contents, often spitting out a “cud” of indigestible exoskeletons and head capsules near the nest entrance. The skunk’s thick fur and a layer of fat provide a degree of protection against the stings they inevitably receive during this process. Other mammals, including foxes, weasels, and bears, are also opportunistic nest raiders, attracted by the nutrient density of a successful bee colony.
Specialized Arthropod and Amphibian Ambushers
A wide variety of smaller predators specialize in ambushing individual bumble bees while they are away from the protection of the colony, typically on flowers. Crab spiders are masters of camouflage, changing their body color to match the white or yellow petals on which they sit. When a foraging bee lands on the flower, the spider strikes with powerful front legs and injects a fast-acting neurotoxin that paralyzes the bee before it can use its stinger. The spider then liquefies the bee’s internal tissues with digestive enzymes and sucks out the nutrients.
Robber flies are aerial predators that hunt on the wing, often perching on exposed spots to launch a swift attack on flying insects, including bumble bees. Some species even mimic the appearance of their bumble bee prey, which may help them approach unnoticed. The robber fly uses its piercing proboscis to stab the bee in mid-flight, injecting paralyzing venom and digestive enzymes before returning to a perch to consume its liquefied meal. Praying mantises are also ambush predators that wait motionlessly in vegetation, using their camouflage and lightning-fast, spiked forelegs to snatch unsuspecting bees.
Amphibians like frogs can be a threat when a bumble bee is distracted by feeding on a low-growing flower or near a pond’s edge. A typical frog hunting strategy involves waiting in cover and using a sudden, sticky tongue strike to capture the bee before it can react. Specialized wasps, such as Beewolves (Philanthus spp.), are highly skilled hunters that sting and paralyze bumble bees, but they do so not for immediate consumption but to provision their underground nests with fresh food for their own larvae.
Avian Hunters of Foraging Bees
Birds that prey on bumble bees have developed specific techniques to circumvent the danger of the sting, often catching the bees in mid-air or after a pursuit. The European Bee-eater is a well-known specialist, catching the bee in its beak and repeatedly hitting it against a hard surface to prepare it for consumption. This process typically involves rubbing the abdomen against a branch to remove the stinger and simultaneously squeeze out the venom before swallowing the meal.
Other insectivorous birds, such as Great Tits and Robins, have also been observed preying on bumble bees, particularly workers near the nest entrance. Flycatchers and Shrikes are also opportunistic hunters of large flying insects like bumble bees, snatching them from the air. Shrikes, sometimes called “butcher birds,” are known for impaling their prey on thorns or barbed wire to hold them securely while they dismantle and eat the insect.