Clover mites (Bryobia praetiosa) are common household invaders that often cause alarm due to their tiny, reddish appearance and tendency to swarm. These pests are arachnids, meaning they are related to spiders and ticks. They appear near homes, particularly those surrounded by lush lawns and gardens, and are considered nuisance pests rather than a genuine threat. They do not pose any medical harm to people or household animals.
Do Clover Mites Bite Humans or Pets?
Clover mites do not bite humans or pets, nor do they transmit any diseases. Their feeding structures are adapted for consuming plant matter, making them incapable of piercing human or animal skin. They are phytophagous, meaning their diet consists exclusively of extracting sap from plants. Pests sometimes mistaken for clover mites, such as chiggers or certain ticks, possess the mouthparts necessary to bite and feed on blood. When a clover mite is crushed, it leaves a dark red stain, which is often misinterpreted as blood, but this stain is the mite’s body pigment and hemolymph.
Identifying Clover Mites and Their Food Source
Adult clover mites measure less than a millimeter long and are typically reddish-brown to dark olive-green. A distinctive feature is their long front pair of legs, which are often held forward and mistaken for antennae. When observed indoors, they generally move in a slow, sluggish manner.
Their primary food source is a wide variety of plants, including lawn grasses, clover, and ornamental plants like alyssum and primrose. Clover mites thrive in well-fertilized, lush lawns, which is why infestations often occur in areas with grass growing against a home’s foundation. They are most abundant in the spring and fall, as these are their cool-season periods of activity.
The mites migrate indoors when outdoor temperatures become too hot or too cold, seeking shelter or a place to lay eggs. They often gather on the sunny sides of buildings, around windows, and in crevices. Once inside, they cannot reproduce or find adequate food.
Preventing and Managing Indoor Infestations
If clover mites are discovered inside, the best method for immediate removal is using a vacuum cleaner with a crevice tool attachment. Vacuuming is recommended because it removes the mites without crushing them, preventing the characteristic red staining on carpets and upholstery. After vacuuming, the sealed bag or canister contents should be disposed of immediately outside.
Long-term management focuses on creating a physical barrier around the home’s perimeter to interrupt their migration path. Homeowners should establish a vegetation-free zone extending 18 to 24 inches outward from the foundation. This strip can be filled with materials like pea gravel, coarse sand, or lava rock, which clover mites find difficult to cross.
It is also important to seal all potential entry points into the structure. This includes caulking cracks and crevices in the foundation, around window frames, and near basement windows. Reducing excessive watering and fertilization near the foundation also helps by discouraging the lush plant growth that attracts large populations of these mites.