Bees and wasps

First issue May 1997

For a printable (PDF) version click here

Many people worry about stinging insects like bees or wasps, especially if they appear to be planning to set up home in or close to the house. These fears are natural, because stings are unpleasant and, to a tiny number of supersensitive individuals, can be very serious. But fears are often greater than the real risk, built up by alarmist press reporting about 'killer bees', 'giant wasps' and the like. The reality is that stings are rare and can usually be avoided altogether if you act sensibly and take the simple precautions we describe later.

Situations do arise where the only practical course is to destroy a nest, but often this is unnecessary. Destruction is also undesirable because bees and wasps do an essential job in the garden and in the countryside generally. Bees in particular pollinate plants, and this is important for both wild and garden flowers and for many agricultural crops. Currently honey bees are threatened by the arrival in this country of a new and damaging parasite, the varroa mite, while in many localities bumble bees are declining. Wasps also take garden pests like caterpillars and greenfly as food for their young.

To help you to do the right thing when you come across them in your garden or house, this note explains a little about their behaviour and suggests what action to take in particular circumstances.

A quick guide to bees and wasps

Social bees and wasps

Bumble and honey bees and the commonest wasps live together as a colony and cooperate to raise their young - they are social insects. The colony always centres on the queen, who lays eggs most of which develop into workers. The workers look after the queen, and help to raise more young and build up the colony. A colony of wasps may run into thousands of workers and of honey bees into tens of thousands. Colonies of bumble bees are smaller - 200 workers at most.

Differences between bees and wasps

All bees feed on nectar and pollen and make nests of beeswax. They have hairier bodies and legs and more subdued colours than wasps. There are about 12 different species of bumble bees in Essex. Wasps, by contrast, make their nests of paper (chewed-up wood) and are predators, taking many other insects.

Solitary bees and wasps

There are many species of solitary bee, including leaf-cutter, mason and mining bees. Many solitary wasps make their nests in holes in the ground, in wood or in masonry, while ant-like gall wasps live inside galls on trees.

... and some impostors

Many hoverflies mimic wasps for self-protection. They are nectar-feeders. Apart from having no sting, they have a distinctive hovering or darting flight and a thicker waist. Often their young feed on aphids.

What should I do about a nest?

If bumble bees or wasps establish a nest in or near your house, such as in the roof space, the first question you should ask is whether you really need to get rid of it, bearing in mind that it will only be occupied until the following autumn. Bumble bees in particular are very docile creatures and while wasps can be more aggressive, they very rarely sting unprovoked. Simple precautions (see below) will usually be enough to avoid stings. To keep them away next year, seal up the entrance hole in the late autumn when the nest will be empty.

If you come across a bumble bee nest in an inconvenient place - compost heaps are a popular choice - then it is easy to move it to a better spot. After dark when all the bees are at home, transfer the nest carefully on to a slate or roof tile set up nearby on top of a couple of bricks. Do this with a spade or by hand, wearing thick gardening gloves. Put plenty of kapok (upholsterer's cotton) on top to serve as nesting material then cover with a large earthenware flower pot with its drainage holeblocked, leaving an inch or so overhang so the bees can get in and out.

If you decide you must get rid of a wasp nest, call in the experts, who will use quick-acting insecticides. DO NOT try crude DIY methods such as pouring in boiling water, which may prove stingingly ineffective.

"Photo by David Corke

What do I do about a swarm of bees?

Swarming is the natural method of increase for honey bees. When the queen decides to swarm she leaves the hive followed by all the mature bees. The young bees left behind then raise a new queen to succeed her. Beekeepers can recognise when a colony is planning to swarm and can take measures to prevent it, but some swarms get away all the same.

A swarm of bees is no threat unless it is interfered with, because the bees get 'high' on honey before leaving their old home. After flying a short way, they form a cluster round the queen, often on a low branch of a tree. Then scouts set off to find a suitable site and, when successful, return to summon the swarm to its new home. Thus a swarm settling in your garden may move on without your needing to do anything, although there is always the risk that their chosen home will be in the roof of your house or behind your shed.

Members of the Essex Beekeepers Association will come to collect swarms and the local police should have a phone number. The beekeeper normally makes a small charge to cover costs and collects in the evening when most of the bees have returned to the cluster. The bees have to be transferred to a box by knocking or shaking the cluster off its perch. Once the queen is in the box the rest of the bees will follow. This means that a swarm can only be collected if it is accessible. If it is inaccessible, such as for example in a cavity wall, then destruction may be the only option and you may need to call in a pest control specialist.

How do I avoid getting stung?

Bees and wasps only attack when they think their nest is threatened, and they may also sting in self-defence. Therefore the basic rule is to avoid any behaviour that they might construe as threatening, especially near the nest.

If you inadvertently disturb a wasp or wild bee nest, try to stay still, because they are programmed to chase and sting whatever moves. (This does not apply to bumble bees, because they usually defend the nest rather than coming out on the attack.) When they have calmed down, retreat slowly. However, once you have been stung a rapid retreat from the nest is best, because one sting provokes others.

Away from the nest, bees and wasps generally approach people out of curiosity rather than malice. Having established that you are not a source of food, they go off about their business. Hence the safest course is to keep still, since waving your arms may be interpreted as a threat. If a bee or wasp settles on you or on your clothing, just wait for it to fly off again or shake it off gently.

Bees and wasps occasionally get entangled in hair and sting in panic, so wear a hat if you are crossing a flightline to or from a nest. This is especially important in windy weather, when they tend to fly lower down in the stiller air.

Only honey bees survive as a colony over the winter. The workers in bumble bee and wasp colonies die out in the autumn and only the queens survive, hibernating through the winter and building a new nest in spring to start a colony from scratch.

Wasps are a special problem in late summer and autumn when the nest starts to run down. Earlier in the season the workers are busy feeding their young and in return receive a sugary secretion. Later on they are unemployed, dozy and desperate for sugar, and they get into drink cans, chew holes in apples and generally make a nuisance of themselves. The best protection at this time is vigilance - look before you sit or put your hands down.

How should I treat stings?

For most people, bee and wasp stings are painful for about half a minute, and later on a swelling develops which is the body's allergic reaction to the venom. This may last for a couple of days before subsiding, itching like a gnat bite. Antihistamine cream and, failing that, an ice pack, may help.

Occasionally swelling may increase to alarming proportions or a rash develop, and if this happens you should see your doctor. You should also seek medical help if the sting is in the mouth or throat because of the risk that the swelling may interfere with breathing. A tiny number of people are hypersensitive to stings and lose consciousness soon after being stung. Get them to hospital as fast as possible.