Wasps are known for their distinctive appearances and intricate paper-like nests, often found hanging from eaves, in attics, or within tree cavities. A common question arises: do wasps reuse these nests year after year?
The Annual Cycle of Wasp Nests
Social wasps, such as yellowjackets and paper wasps, follow an annual life cycle. In spring, a single queen, having overwintered in a sheltered location, emerges and begins to construct a new nest. She chews wood fibers, mixing them with saliva to create a papery pulp, which she molds into the initial structure. This small, golf-ball-sized nest contains the first cells where she lays her eggs.
Once the first worker wasps hatch, they expand the nest and forage for food. The queen then focuses solely on laying more eggs, leading to rapid colony growth throughout the summer. Nests can grow considerably, sometimes reaching the size of a football or larger.
As autumn approaches, the colony’s life cycle nears its end. The original queen dies, and worker wasps perish due to the cold and lack of food. Only newly fertilized queens survive the winter by finding new, sheltered places to hibernate. These new queens will then start their own colonies in different locations the following spring, ensuring the old nest is abandoned. Building a new nest each year helps prevent the buildup of diseases and parasites.
Fate of Abandoned Nests
Once a wasp colony dies off in late autumn or early winter, the nest is left abandoned. These structures are not re-inhabited by wasps in subsequent years. The abandoned nests typically decay over time, breaking down due to exposure to weather elements.
Other insects or small animals may occasionally scavenge material from the old nests. The papery substance of the nest can also become a winter retreat for other opportunistic pests, such as spiders or small rodents, seeking shelter from the cold. Once empty, these nests generally do not pose a threat to humans.
When Removal is Recommended
Given that wasps do not reuse their nests, removing an abandoned nest is often unnecessary, especially if it is in an out-of-the-way location. An inactive nest, identifiable by a lack of wasp activity, can safely be left alone, particularly in winter after a few hard frosts have occurred. Some may even choose to leave them as a deterrent, as a pre-existing nest might signal to new queens that the spot is already occupied.
However, there are circumstances where removal is advisable. If an abandoned nest is in a location where it might cause concern or obstruct work, such as during renovations, its removal can be practical. For active nests, removal is recommended if they are in close proximity to human activity, such as near entryways or play areas, or if individuals in the household have allergies to wasp stings. Wasps can become aggressive when their nest is threatened, and stings can be painful, with multiple stings potentially leading to severe reactions.
If removing an active nest, safety precautions are important. Wasps are less active during the evening or early morning when most of the colony is inside the nest. Wearing protective clothing, including long sleeves, pants, gloves, and a face covering, is important to minimize skin exposure. Maintaining a safe distance and avoiding sudden movements around the nest can prevent agitation. For larger or more aggressively located nests, contacting a professional pest control service is often the safest and most effective approach.