You may be spotting dead bumblebees lying on pavements near you during the summer months. There are several reasons for this, some related to the weather and some very much due to humans.
Bumblebees are social insects that live in colonies maintained by very active workers with a relatively short lifespan of 4–6 weeks. This means that, in a relatively short time, older bees die off. To prevent disease from making its way through the colony, healthy young workers remove their dead, moving them far from the colony.
Another factor is the weather. It was the warmest June on record in England (and the second hottest for the whole UK) in 2026, and other high temperatures are expected this summer.
The life of bees explored by David Attenborough.
Thermal stress in bees is caused by this kind of extreme heat. Prolonged heat exposure alters development and threatens long-term population stability.
Other elements play a part in bee deaths. Pesticide and herbicide use is commonplace, and these chemicals affect the fitness of bees, causing them to die off. However, these chemicals not only affect bees directly, but can also remove important plants that they rely on for food, causing them to starve.
Dandelions, for example, are a massively important nectar source for bees, but are also commonly controlled with herbicides. So don't weed your garden or pull them out.
Pesticide use is one of the historical key causes of loss of bees. Pesticides applied to reduce insects feeding on crops are, somewhat ironically, responsible for harming a group of animals responsible for crop pollination.
The EU and the UK have banned the use of the most harmful neonicotinoids. However, pesticides are still routinely used, with harmful knock-on effects on pollinators. Insecticides such as organophosphates, synthetic pyrethroids and phenylpyrazoles cause paralysis and death, as well as disrupting bees' ability to navigate.
Phenological mismatch is when two organisms that depend on each other appear at the wrong time. With a changing climate, this is happening.
For example, plants that bees depend on may be in flower when the bees aren't around. Essentially, they are flowering at a time of year when the bees aren't there. Bees could come out of hibernation too early and not have any nectar to feed on, or, conversely, flowers could bloom before the bees appear. This, of course, is a disaster for both flowers and bees.
Bees under threat
Insects are the most diverse and abundant group of animals on the planet, but despite this dominance, they are the most threatened.
But we really need them. They provide so much support for our planet as decomposers, pest controllers, food for other animals and generally by keeping our systems clean and tidy. Scientists call these roles ecosystem services. However, one such service they provide is directly important to us and disproportionately carried out by one group of insects: bees. That service is the pollination of our crops.
When it comes to pesticide use, be a thoughtful and informed consumer. Support local, sustainably produced food where possible and, if feasible, buy from farmers who use nature-friendly practices. This does not necessarily mean choosing organic products, but rather considering how food is produced and the environmental impact of different farming systems.
As a homeowner, explore nonchemical alternatives first, and apply any treatments sparingly and responsibly to minimize harm to beneficial insects and other wildlife.
One of the simplest ways to address habitat loss for bees is to make room for native species. Plant a diverse range of native flowering species, and leave some areas of lawn unmown. This can help create safe havens for bees.
In the short term, there is one thing that people can do to help bees in distress. Providing sugary water to a bee you see struggling on the pavement on a hot summer's day can help revive it. A mixture of sugar and water will do the trick at a two-to-one ratio of sugar to water.
Moving the bee, if safe to do so, to a flower or a shady spot is also advised. But please do not do this if you have allergies or are likely to get stung.
