Spotting tiny red bugs on your windowsill? Those small red spiders are usually clover mites, not true spiders. In my experience working in DC metro homes, these mites spike in spring and fall. They never bite, but they do leave red stains if you crush them.
Even though people call them small red spiders, they’re actually plant-feeding arachnids. To learn about real spiders, visit our spiders guide.
What Are They?
According to the University of Florida, clover mites (Bryobia praetiosa) are plant-feeding arachnids in the Tetranychidae family. All adults reproduce without mating, which is how populations grow so fast.
Adults measure 0.75-0.85 mm long. Their first pair of legs is extra long, almost double the body length. Bright red larvae turn brick-red or greenish-brown after feeding. Per the University of Maryland Extension, crushed mites leave rusty-red stains on light surfaces.
Learn more on our What Are The Tiny Red Bugs? page.
Life Cycle and Seasonal Timing
Clover mites have two outdoor generations per year, one in spring and one in fall. They go dormant in summer heat and overwinter as eggs. Spring eggs hatch when soil temps rise above 45°F. Fall eggs hatch as temps drop below 85°F in September.
Where They Come From
These mites feed on cool-season grasses like Kentucky bluegrass and tall fescue, plus clover and ornamental plants. Outbreaks often follow heavy lawn fertilization, notes the University of Missouri Extension.
In early spring and fall, masses of mites climb sunny south and east walls looking for shelter. Window screens don’t stop them. They slip through holes smaller than 0.2 mm. Once inside, they wander slowly, can’t reproduce, and dry out in days.
Damage and Risks
On lawns, heavy feeding causes silvering or bronzing of grass blades. Inside homes, they’re just a nuisance. No biting, no disease risk.
If the mites are showing up in large numbers, here’s how to deal with them.
How to Check for Them
Look at sunny foundation areas in March through May and September through November for silvery grass and tiny red specks. Indoors, press clear tape on the mites to confirm. Red specks on the tape prove clover mites.
How to Get Rid of Them
DIY Removal
- Vacuum visible mites and toss the bag right away
- Seal cracks around windows and doors with caulk or weatherstripping
- Create a barrier: Keep an 18-24 inch plant-free zone of mulch or stone against your foundation
- Adjust lawn care: Cut back on spring fertilization, which feeds the mites’ food source
Prevention
Once you’ve cleared the current mites, these steps keep them from coming back.
- Foundation buffer: Maintain an 18-inch mulch or stone strip next to walls
- Seal entry points: Caulk cracks around windows, doors, and utility lines
- Landscape smart: Slope soil away from the foundation. Use hardscape within 2 feet of walls
- Fertilize carefully: Feed lawns in mid-autumn instead of early spring to avoid fueling mite populations
Small Red Spider vs Red Spider Mite
Clover mites don’t spin webs. Two-spotted spider mites feed on plant leaves under fine silk webs, per the University of Minnesota Extension. Clover mites invade homes while spider mites stay on plants. For more, see Are Arachnids Insects? or Is a Spider a Bug?.
Case Study: Spring Mite Spike
In DC metro homes, I’ve seen windowsills covered with clover mites each spring. One customer wiped red stains off their patio and called us right away. After a single exterior treatment, the problem dropped 90% within 48 hours. A second visit cleared the rest and the stains washed away.
Related Guides
If you need help with small red spiders, call us at 703-683-2000 or email info@bettertermite.com.
