Identifying wasps becomes necessary at times to determine if the wasp living under the awning of your porch, in a nearby tree, or in a burrow on your lawn is beneficial or dangerous. Most wasps possess a severe sting and will sting repeatedly if threatened. Among the aggressors are yellow jackets, giant hornets and bald-faced hornets. Other wasps, like mud dauber wasps, are not aggressive and typically go about their business killing off harmful insects and scavenging.
Determine the type of nest the large wasp is building. Some wasps are digger wasps, which use mud to build long tubes of dried mud on the sides of building. They are not aggressive and generally go about their own business. Paper wasps, which are typically more territorial and aggressive towards people build paper nests. They sometimes hang them from eaves or in bushes, or conceal them inside the walls of your home, abandoned animal burrows or rotted logs or tree trunks. Sometimes the nest will look like a few cells suspended from your eave; other times it is a large round or pear-shaped structure as large as a basketball.
Secure a specimen. It is best to use a dead wasp, although care must still be taken as wasps are known to continue stinging for a period of time after their death. Use tweezers to collect the wasp, picking it up gently by a wing, and place it in a jar. Never try to capture or kill a live wasp.
Study the wasp itself. Use a magnifying glass, and place the dead wasp on a piece of white paper for better visibility. Use your tweezers to handle the wasp.
Look for colouring. Some wasps, like paper wasps, are flashy in their markings, having usually either white, yellow, red, or orange bands, stripes or spots. Some are solid black, brown or orange. Digger wasps often have an iridescent sheen to their black bodies, making them appear blue or purple in sunlight.
Determine the wasp's body type. Yellow jackets and other paper wasps are shaped much like bees, but with a longer, slimmer abdomen and a 'waist' where the thorax and abdomen meet. A mud dauber wasp's waist is extremely exaggerated, looking almost like a stalk coming off the abdomen.
If you find a wasps' nest away from populated areas, it is best to leave it alone. Wasps serve an important role in the ecosystem.
Never approach a wasp nest. Wasps will fight to defend not only the nest, but territory, as well. If dealing with a large nest of aggressive wasps, bring in the professionals to neutralise the problem. Always wear protective clothing when working around bees and wasps.