Bald-faced hornets, scientifically known as Dolichovespula maculata, are commonly encountered across North America. Despite their intimidating appearance and common name, they are not true hornets but rather a species of aerial yellowjacket. These social insects are recognized for their distinctive markings and the large, paper-like nests they construct. Their behavior is primarily defensive, meaning they typically only exhibit aggression when their colony or nest is perceived to be under threat.
Recognizing Bald-Faced Hornets
Identifying bald-faced hornets involves observing their unique physical traits and the structure of their nests. These insects feature a striking black and white or ivory coloration, distinguishing them from the more common yellow and black wasps. Their head is predominantly white, which gives them their common name, and they have three white stripes near the end of their body. Workers typically measure between 1/2 to 5/8 inches in length, while queens can be slightly larger, reaching up to 3/4 inches.
Bald-faced hornets construct distinctive paper nests that are typically gray and tear-drop or football-shaped. These nests are made from chewed wood fibers mixed with saliva, giving them a papery texture. They are usually suspended in elevated locations, such as tree branches, shrubs, utility poles, or on the eaves and sides of buildings. These nests can grow quite large, sometimes reaching up to 14 inches in diameter and 23 inches in length, and may contain 400 to 700 workers by late summer.
Their Defensive Nature
They become highly protective if their nest is disturbed or if humans or animals approach too closely, often within a range of 3 to 10 feet. Specific triggers for their defensive actions include vibrations, sudden movements, or loud noises near the nest.
When attacking, bald-faced hornets are capable of stinging multiple times because their stingers are smooth and do not become embedded in the skin like those of honey bees. Their venom causes immediate pain, swelling, and itching. A unique defensive mechanism they possess is the ability to squirt venom from their stingers, often aiming for the eyes of a perceived threat. This sprayed venom can cause immediate watering of the eyes and temporary blindness.
Minimizing Encounters
To avoid provoking bald-faced hornets, maintaining a respectful distance from their nests is advisable. If a nest is spotted, especially one located in a high-traffic area, it is important to avoid sudden movements or swatting at individual hornets, as this can trigger a defensive response from the colony. Wearing light-colored clothing can also be beneficial, as dark colors may attract stinging insects. If a hornet lands on you, gently brush it off rather than swatting.
When a bald-faced hornet nest is found on your property, particularly near human activity, professional removal is the safest approach. Attempting to remove a nest yourself can be dangerous due to the hornets’ aggressive defensive nature and their ability to sting repeatedly. Pest control professionals typically have the necessary equipment and expertise to handle removals safely, often performing the task at night when the hornets are less active and inside the nest. Implementing preventative measures such as sealing cracks and crevices in your home and trimming overgrown vegetation can help deter nest building near structures.