Wasp Killer Sprays

Individual wasps and small numbers you can see, in and around the home and garden - the odd wasp in a room, or a few around a doorway. A contact spray is not the tool for a nest. Products differ in where they can be used and how far they project, so check the label to make sure the spray suits the situation before you buy.

Check before you spray. Wasps are bright yellow and black, smooth and narrow-waisted. Honey bees are smaller, hairier and browner; bumblebees are large and furry. Neither should be killed, and a beekeeper will usually collect a honey bee swarm free of charge. If what you are looking at is round, fuzzy and largely uninterested in you, let it find its own way out. Our guide to getting rid of wasps yourself covers telling wasps, bees and hornets apart.

Use them with care and exactly as directed on the product label. Keep children and pets away during application and until it is safe to return to the treated area, as the label states. Avoid use near food, food preparation surfaces and eating areas unless the label specifically allows it, and never spray towards a person.

Many are designed for fast knockdown of the wasps they contact, but results vary by product and by how it is used. Use the spray exactly as directed and choose one suited to the job - a spray meant for individual wasps indoors is a different product from one intended for treating a nest at a distance.

A contact spray is for individual wasps rather than for a nest, and treating a nest with one is where people get into trouble. For a nest you have located and can safely reach, a nest killer powder is the right product - returning workers walk through it and carry it inside, which is what actually reaches the colony. Where a spray is specifically labelled for nest treatment, use it only as the label directs and only where you can see and reach the entrance from the ground. Treat at dusk or first light, cover up in light-coloured clothing with long sleeves, trousers, gloves and eye protection, and plan your exit before you start. Do not treat from a ladder. A nest in a wall or roof void, out of reach, or beside a doorway or play area is a job for a professional, and so is any nest if someone in the household has a sting allergy.

No. Sealing it traps workers inside and pushes them to chew a new way out, often inwards into the building rather than back outdoors. Leave the entrance open until all activity has stopped, then seal the gap so the site cannot be used again.

Report it rather than treating it. The Asian, or yellow-legged, hornet is an invasive species: look for a mostly dark, almost black body with a single yellow-orange band near the tail, yellow-tipped legs and an orange face. Do not approach the nest and do not spray it. Photograph it from a safe distance if you can, report it through the Asian Hornet Watch app or the online reporting form, and leave it for the authorities.

Wasps usually come in through open windows and doors rather than nesting inside, so the fix is normally physical: fit insect screens and keep doors closed at peak times. Where a spray helps, treat the entry point and surrounding surface as the label directs rather than spraying into the room.

Wasps that were away foraging when you treated will return to the entrance for a few days, so some continuing traffic is normal. Watch whether it falls day on day. If activity is unchanged after a week, the spray has not reached the nest itself - common where the nest sits well back inside a cavity and the visible hole is only the way in, and the usual reason a spray struggles where a powder at the entrance would not. That is the point to call a professional rather than treating again.