What eats bumblebees?

Bumblebees have many predators, some of which are mammals and birds. These predators have co-existed with bumblebees for thousands of years and are not a cause for conservation concern. It is the problems caused by humans, like habitat loss, pesticide exposure and climate change, which make natural predation more of an issue for bumblebee populations.

The main mammalian predators are badgers, which use their strong claws to dig up nests and eat the larvae and stored nectar and pollen. Badger predation seems to be more likely to happen when conditions are dry and it is harder for badgers to find their preferred food source – earthworms. Badgers tend to dig up large nests, possibly because they can smell them more easily. Large nests have been active for awhile and may have already produced new queens and males so, although it can be upsetting to find a predated nest, it might not mean disaster.

Sometimes a badger is disturbed or driven off by the bumblebees defending themselves before too much damage is done, particularly if the nest is well protected by natural features like tree roots. If you find a nest that has been dug up, you can provide some protection by propping something over the top to stop wet weather also impacting the bees. Otherwise, it’s best to leave them alone and let nature take its course.

It is important to remember that badgers and bumblebees have co-existed for many years.  Badger predation is a natural process and is not thought to be a major driver of population declines. There is no evidence that bumblebee declines at a national level match badger population increases.

Birds often eat adult bumblebees. In particular, robins and great tits have been found to catch bumblebees, rub them on branches to remove the stings, and then to peck out the insides! Again this is a natural process and not something that is causing large declines in bumblebee populations.

Other predators and parasites are wasps and flies, some of which lay their eggs inside live bumblebees or bumblebee nests.

Spiders can also eat bumblebees—for example the Crab spider hides on flowers, waiting for insects to come along to feed. It then grabs them with its front legs, and injects them with venom that causes paralysis and a quick death, before sucking out the contents of the body.