Lycosidae family
Spider
1 to 2 inches including legs
Brown or gray with dark stripes
1 to 3 years
About the Wolf Spider
Wolf spiders are large, hairy, fast-moving ground-hunting spiders that do not build webs. Wolf spiders are Michigan's most commonly encountered large spider. They are not dangerous to humans and their bite (rare) produces mild, temporary pain similar to a bee sting.
Habits & Behavior
Wolf spiders live outdoors under rocks, logs, leaf litter, and mulch. They hunt by chasing prey rather than trapping it in webs. They enter homes in fall when temperatures drop, hiding in basements, crawlspaces, garages, under appliances, and in undisturbed closet corners. Females carry their egg sacs attached to the abdomen and later carry newly-hatched spiderlings on their back.
Signs of a Wolf Spider Infestation
Large hairy brown or gray spider running across the floor
Spiders visible in basements, garages, crawlspaces, and bathtubs
No webs (wolf spiders do not build webs)
Female wolf spiders carrying a round egg sac
Increased indoor sightings in October and November
Wolf Spider Pressure in Michigan
Wolf spider indoor activity peaks in October and November as temperatures drop below 50 degrees F. Lakefront properties, wooded subdivisions, and homes with landscape beds adjacent to the foundation see the heaviest wolf spider pressure. Walkout basements and attached garages are primary entry points.
How BTR Treats Wolf Spider Infestations
BTR uses exterior perimeter spray applications focusing on foundation, garage doors, landscape beds, and known entry points. Interior treatments target basements, garages, and crawlspaces. 90-day warranty. Quarterly general pest programs maintain year-round control.
Prevention Tips
Seal gaps at garage door sweeps, basement windows, dryer vents, and foundation penetrations. Move mulch and landscape beds 12 inches from the foundation. Reduce outdoor lighting (which attracts prey insects that attract spiders). Keep basement and garage clutter minimal.
Frequently Asked Questions About Wolf Spiders
Are wolf spiders dangerous?
No. Wolf spiders are not considered medically dangerous in Michigan. Their bites are rare and produce mild pain, redness, and minor swelling similar to a bee sting. No Michigan spider species is medically significant except the rare brown recluse (which is not native to Michigan but occasionally found in shipped goods).
What is the difference between a wolf spider and a brown recluse?
Wolf spiders are larger (1 to 2 inches with legs), hairier, and have 8 eyes in 3 rows. Brown recluses are smaller (1/4 to 1/2 inch), smooth, have 6 eyes in 3 pairs, and show a distinctive violin-shaped marking on the cephalothorax. Brown recluses are not native to Michigan.
Why are wolf spiders in my basement?
Wolf spiders enter basements and crawlspaces in fall seeking warmth, humidity, and prey. Basement light near windows attracts their insect prey, drawing spiders indoors. Sealing basement windows and garage doors prevents fall entry.
Should I kill every spider I see?
No. Most Michigan spiders are harmless and provide beneficial indoor pest control (eating flies, gnats, mosquitoes, other pests). Wolf spiders and cellar spiders can be left alone unless their presence causes distress. Professional treatment reduces populations without requiring hand-to-hand combat.
Does BTR treat outside for wolf spiders?
Yes. BTR perimeter programs treat the foundation, garage door thresholds, eaves, landscape beds, and common entry points with residual spray chemistry. This prevents fall wolf spider migration indoors.
Wolf Spider Problem? BTR Can Help Today
Free inspection. Licensed Michigan exterminators. 90-day warranty on most services.