What are house yellow jackets?
Yellow jackets are predatory wasps that typically nest in the ground. They get their name from the yellow and black markings on their bodies. Yellow jackets are often mistaken for bees due to their similar size, shape, and coloring, but closely looking at the yellow jacket wasp reveals they have less hair and lacks the rounded abdomen and long hind legs of pollen-carrying bees.
A single yellow jacket colony may house between 1,500 and 15,000 members. The queen yellow jacket lays her first eggs in the spring after hiding out for the winter alone in a protected place. Typically all the other members of her hive perish in the winter and the queen lives to build a new hive in the spring. She will rear over a thousand adult yellow jackets by the year’s end. A colony may contain 1,000 or more workers by fall. Similar to honeybees, the colony is comprised of sterile female workers with males emerging at mating time.
Here in California, when late summer arrives and everything is crispy dry, yellow jackets hit their peak and the calls from concerned properties owners increase. That’s because food is harder to find and their nests are hitting maximum capacity.
Signs of yellow jacket infestation
Yellow jackets typically nest in the ground, often in abandoned burrows of gophers, moles, voles, and ground squirrels. They also build nests under lifted concrete, in tree hollows, and in other crevices large enough to house the thousands of insects that make up their colony.
Interestingly enough, yellow jackets fly very fast (faster than paper wasps) and erratically. They also have a tendency to hover around food or even in your face.
When yellow jackets nest in close proximity to people, encounters are likely to happen. It is very common for nests to be mowed over or for children and/or pets to stumble upon a nest while playing. The aggressive nature of yellow jackets means they’re likely to attack. Yellow jackets may also invade picnics, BBQs, and other outdoor events where sugary drinks and delicious food attract them.
In the video below, Smith's Pest Management captured yellow jackets in Palo Alto, California nesting in a rock wall.