How to deal with wasps in your home
Although wasps benefit the environment by controlling other small pests and clearing away dead insects, their stings are painful and can be serious if you're allergic to them.
How to identify a wasp
Wasps measure about 1.6 cm long and have a striped yellow and black body. Two species of wasp are found locally – 'Common wasps' and 'German wasps'. Both are known for their sting.
Where do wasps live?
Nests can normally be found in holes in the ground or inside hollow trees, though they feel equally at home in sheds, wall cavities, eaves and roofs.
What do wasps eat?
Wasps favour fruit and nectar, insects and dustbin waste. The workers feed on liquids. All wasps feed their young on meat such as insect larvae.
How do I know if I have a wasp problem?
Unusually large numbers of wasps around your home are an indicator of a wasp nest in close vicinity. You might also notice a nest that has been constructed.
Are wasps harmful?
Wasps can give a painful sting, and unlike bees they can sting repeatedly. For a minority of people the venom in their sting causes anaphylactic shock which can be fatal.
An ordinary sting can be treated with ammonia, alcohol or cold poultices, followed by antihistamine ointment. But seek medical help immediately if you are stung in the mouth or neck, or if you experience giddiness, nausea, unusual swelling or extreme pain following a sting.
Because the venom in wasps contains a pheromone that causes other wasps to become more aggressive, it's not advisable to swat one near its nest or other wasps.
Things you might not know about wasps
Wasps live in colonies that form self-contained communities, each following a caste order of queens, males and workers.
The only wasps that survive the winter are young fertilised queens. They emerge from hibernation in the spring to build new nests. Initially the queen lays 10–20 eggs and when they hatch into larvae she feeds them until they become workers. The workers then forage for food, feed the new larvae and defend the nest.
In late summer, the colony produces males and new queens. They fly away to mate and the queens then find a place to hibernate. The cold weather eventually kills the males, workers and foundation queen.
Although wasps are fond of sweet things, they don't have the nectar-sucking mouthparts of bees. Towards the end of the summer the workers turn their attention to sweet substances, which is why they become a nuisance to people at this time.
A wasp uses its sting for killing prey, but it also uses it effectively for defending itself. The sting has associated glands which produce venom, but as it's in small amounts it doesn't normally cause extreme harm.
How to exclude them from your home
Keeping wasps at bay is simple, you just have to make sure they don't have access to anything sweet. You can do this by making sure that:
Dustbins have tight-fitting lids
Food is covered
Scraps aren't left to build up around your sink
Fallen fruit is cleared from your garden
Don't forget, the venom of the wasp contains a pheromone which acts as an alarm. This means that when a wasp has stung something or been killed, other wasps will become more aggressive; so killing wasps may just enrage their nearby friends.
Dealing with a wasp nest yourself is not recommended, and you should always contact a professional pest controller.
Can the council help?
Your local council will have its own policy on pest removal. A fee may be charged. You will need to make contact with the Environmental Health Department of your local council to report the problem.