The short version
Around San Mateo, honey bees usually swarm April through June. Swarms are usually calm and often move on. Wall colonies need removal, ideally alive, comb and all. Carpenter bees just need the wood treated and painted.
- Never seal a hole bees are using.
- Wall colonies need the comb taken out.
- Paint bare wood to deter carpenter bees.
- Ask about live removal first.
Homeowners and renters in San Mateo with a swarm, a wall colony or carpenter bees.
What to look for
Spraying alone leaves comb and honey behind. A wall colony can reach tens of thousands of bees. Trouble starts when they move into a house. Most bees are helpful pollinators.
- 1Bees streaming in and out of one gap.
- 2A buzzing sound inside a wall.
- 3Dark, sticky stains on a ceiling or wall.
- 4A swarm hanging from a branch or fence.
- 5Round, clean holes in eaves or deck boards.
- 6Sawdust under holes in bare wood.
Why it’s worth acting soon
- Wall colonies grow larger every season.
- Comb can melt and leak honey into walls.
- Old comb attracts ants, beetles and moths.
- Carpenter bee tunnels get longer each year.
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San Mateo Bee Season Timeline
Spring
Activity begins as temperatures rise.
Summer
Peak season — populations grow fast.
Fall
Pests seek shelter; prevention matters.
Winter
Reduced activity; indoor risk remains.
Treatment options and typical costs
Live Honey Bee Relocation
$150-$500
The bees are collected alive and moved to a hive.
- Time
- 1-3 hours for a swarm; longer for established colonies
- Best for
- Swarms and reachable colonies
Structural Hive Removal
$500-$1,500
The wall is opened and the bees and comb removed. Then it's cleaned and sealed.
- Time
- 2-6 hours depending on access and repairs
- Best for
- Colonies inside walls, soffits or attics
Carpenter Bee Treatment
$150-$450
Holes are treated, then filled. Painting or staining the wood helps keep them away.
- Time
- 1-2 hours per visit; spring follow-up often recommended
- Best for
- Round holes in bare wood
Integrated Pest Management (IPM)
$200-$800
Sealing gaps, screening vents and follow-up checks.
- Time
- Inspection plus seasonal monitoring
- Best for
- Keeping bees from moving back in
Prices are typical published ranges. Ask what’s included before you compare quotes.
Honey bees rarely settle in a basement, but a window well or a gap around a pipe can be the start of a route into the walls above.Which bees show up around San Mateo.
Western carpenter bees, including the big valley carpenter bee, bore into bare wood around San Mateo. Bumble bees nest in the ground or old insulation. Their colonies die off each fall. Small ground-nesting bees in spring lawns are harmless. They're best left alone. Honey bees are behind most calls in San Mateo: swarms in spring, and colonies that move into walls.
Local bees conditions in San Mateo.
Across San Mateo, the area is mostly urban, so bees pressure can differ from one block to the next depending on how tight the entry points are and how much food, water, or shelter is close by. An inspection in San Mateo usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Knowing San Mateo's seasonal timing lets you schedule treatment before the busy stretch rather than after it, which usually means faster service and a more accurate quote. A provider who works San Mateo and California every day can point out the specific conditions that matter most here, and getting the scope, price, and follow-up terms in writing makes it easier to compare options. San Mateo sits in a mediterranean climate, and that sets the pace for bee activity here: spring and summer (swarming and colony growth).
Fall is the easiest time to seal gaps along the foundation and siding, once bee traffic has slowed and before next spring's scouts start looking.Swarms: what to do.
Scouts are hunting for a new home. It's usually calm and moves on within days. Keep people back. a beekeeper or removal service. A swarm is a colony on the move.
Bees in the wall.
Don't seal the hole, and don't just spray it. Trapped bees may come into the house. The fix is a cut-out. Bees and comb come out, then the wall is closed. In older homes around San Mateo, check soffits, chimneys and gable vents first. Homes from San Mateo out to San Francisco and Oakland see the same entry points: soffits, vents and wall gaps. Steady traffic at one gap means a colony inside.
Carpenter bees.
They drill round, half-inch holes in bare wood. Treat the holes, fill them, then paint the wood. Painted wood is far less attractive to them. Carpenter bees look like bumble bees with a shiny, bare abdomen.
A year of bees in San Mateo.
- Winter: lows near 43°F in San Mateo. Honey bees cluster inside. - Spring: swarm season, April through June. - Summer: highs near 78°F in San Mateo. Watch for honey stains on walls. - Fall: bumble bee colonies die off. Seal gaps once bees are gone.
Bee, wasp or hornet?
- Yellowjacket: bright yellow and black, nests in the ground. - Honey bee: fuzzy, golden brown, about half an inch. - Bumble bee: big, fuzzy, black and yellow. - Carpenter bee: like a bumble bee, with a shiny bare abdomen. - Wasp: smooth, narrow waist, long legs.
If you get stung.
Wash the area and use a cold pack. An antihistamine eases itching. 911 for trouble breathing or a swollen face or throat. Scrape the stinger out quickly with a fingernail or card.
Live removal: what it involves.
They open the wall and gently vacuum the bees. Then they cut out the comb. The bees go to a managed hive. Then the space is cleaned, sealed and closed. A specialist finds the colony, often with a thermal camera.
What to tell the removal company.
- A photo or short video, taken from a safe distance. - Where the bees go in and out. - How high up the spot is. - How long you’ve noticed them. - Any stains, sounds or smells inside. - Whether anyone at home is allergic.
Ground bees in the lawn.
They're gentle and rarely sting. They leave within a few weeks. Thicker grass and regular watering make the lawn less inviting. Small bees over bare spring lawn are usually mining bees.
Keeping bees from moving back in.
- Repaint or restain bare wood every few years. - Remove all old comb. Its scent draws new swarms. - Seal the entry gap once the bees are gone. - Screen attic, gable and crawl vents. - Cap open pipes, posts and fence rails.
Where colonies settle.
- Hollow trees and fence posts: often fine to leave. - Chimneys: a cap with screen keeps swarms out. - Attics: gable and soffit vents are common entries. - Sheds and garages: gaps under eaves and doors. - Meter and irrigation boxes: small, dark and dry. - Grill covers and unused equipment: check in spring.
Can I just spray them?
Still, spraying a wall colony usually backfires. Dead bees and comb stay inside, rot, and leak honey. Pesticide labels also limit spraying around bees. Live removal is usually the better choice. Honey bees aren't federally protected.
Kids, pets and bees.
Keep pets away from swarms and wall entrances. Dogs stung in the mouth or throat need a vet quickly. Cover sweet drinks outside. Teach kids to stay calm and walk away from bees.
When a swarm shows up.
Swarming bees are usually calm. They have no hive to defend. Most move on within a day or two. Keep people and pets back. A beekeeper may collect it. In spring, a swarm may hang from a branch or fence.
Questions to ask before you sign.
- How will you seal the entry afterward? - What kind of bee is it? - Will you remove the bees alive? - Will you take out all the comb and honey? - Who repairs the wall or soffit?
What affects the price
- Swarm pickup versus a colony inside a wall.
- How high the bees are, and whether a lift is needed.
- Opening and repairing walls, soffits or ceilings.
- Comb and honey cleanup.
- Number of carpenter bee holes.
- Whether bees can be removed alive.
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What’s your biggest bee concern?
When to call for help
right away if anyone in the house is allergic. if a swarm hasn't moved on in a few days. Call if bees use a gap in your walls or roof.
What you can do yourself
A beekeeper or removal specialist can often save the bees. Swarms and wall colonies are not. Treat, fill and paint. Carpenter bee holes are a fair DIY job.
Bees in San Mateo
With about 21 inches of rain a year and summer highs near 78°F in San Mateo, spring bloom is steady and swarms are common. Winter lows near 43°F in San Mateo send honey bees into a tight cluster; they don't leave the nest. In denser parts of San Mateo, colonies turn up in walls, soffits, signs and utility boxes.
Local research
Bees in San Mateo, CA: what the public record shows
Before you compare quotes, it helps to know which bees actually live in California, when they are busiest around San Mateo, and what the state figures look like. Everything below links to the agency or university page it came from.
Honey bee colonies, January 1, 2026 (operations with five or more colonies)
Managed hives are the source of the spring swarms that end up in homes and trees; the state table is on page 7 of the report.
USDA National Agricultural Statistics ServiceAfricanized honey bee arrival in California
Since then AHB 'have become the majority of feral bee colonies found in nature' in Southern California.
UC Agriculture and Natural ResourcesBee species recorded in California
- Western honey bee (European honey bee) (Apis mellifera) — Managed colonies are surveyed by USDA NASS in the listed states; swarms leave hives in spring and move into wall voids, chimneys, and trees. If a colony is killed and not remove…
- Africanized honey bee (Apis mellifera scutellata hybrids) — Visually indistinguishable from European honey bees; far more defensive and swarm more often. 'They entered Texas in 1990, Arizona and New Mexico in 1993, and California in 1994…
- Bumble bees (Bombus spp.) — Social native bees; 'Nests are initiated by a single female (queen) in the spring' in 'a small cavity like an abandoned rodent burrow' (WSU). They 'can sting multiple times; sti…
When bees are busiest around San Mateo
Swarms come 'usually in the spring but sometimes at other times of the year when local conditions permit' (UC IPM). AHB has colonized 'all Southern California counties, and the southern Central Valley' as of 2008 (UC Riverside CISR).
UC IPM: 'in some areas your only option will be to hire a structural pest control company', and pesticides labeled for killing bees inside structures 'are available only to licensed pest control operators'. Killing a colony in place risks fermenting honey seeping through drywall. San Diego County notes AHB 'follow and attack intruders for up to a quarter mile away'.
Rules that apply in California
For context, nationally
- 788 deaths (an average of 72 deaths per year) — Sting deaths, hornets/wasps/bees, 2011–2021. CDC MMWR
- 84% — Share of sting deaths among males, 2011–2021. CDC MMWR
Sources: Honey Bee Colonies (August 2026); UC Agriculture and Natural Resources; CDC MMWR; African Honey Bee, Africanized Honey Bee, Killer Bee (EENY-429 / IN790); Apidae: Bumble Bees (Bombus spp.) — Hortsense. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep bees away
- Seal gaps in soffits, vents and siding before spring.
- Screen attic and crawl vents.
- Paint or stain bare wood to deter carpenter bees.
- Fill old carpenter bee holes after treatment.
- Remove old comb so new swarms aren’t drawn in.
- Keep empty bee boxes and hives closed up.
A good bee quote names the bee, says whether live removal is realistic, and lists comb removal, cleanup, sealing and any repairs separately.Did you know?
Honey bees communicate the location of flowers with a “waggle dance.”
Male carpenter bees can’t sting. They just hover and bluff.
Questions people ask
How much does bee removal cost in San Mateo?
A swarm pickup is often $75–$250. Wall colonies cost several hundred dollars or more, plus repairs.
Can honey bees be moved instead of killed?
Often, yes. Swarms and many wall colonies can be removed alive.
A swarm landed in my yard. What should I do?
Swarms are usually calm and move on within days. A local beekeeper may collect it.
Should I seal the hole where bees are going in?
No. Sealing traps the colony inside. They may get into the house. Remove the colony and comb first.
What happens if comb is left in the wall?
It can melt in summer heat and stain walls. It also draws ants, beetles and moths.
Are carpenter bees dangerous?
Not really. Males can't sting, and females rarely do. They do bore into bare wood, so paint or stain it.
When do bees swarm in San Mateo?
Usually April through June. A warm, sunny spell after bloom often sets it off.
Do bees come back after removal?
They can, if comb stays or the gap isn't sealed. The scent of old comb draws new swarms.
How much does live bee relocation cost?
HomeAdvisor's 2026 bee-removal benchmarks estimate paid live relocation at $100 to $800, with the upper end reflecting colonies that must be cut out of a structure and rehoused.
How much does carpenter bee treatment cost?
Seventy-five to $500 is HomeAdvisor's 2026 benchmark for carpenter-bee treatment, and local prices vary.
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Sources (10)
The facts in this article come from the public sources listed above. Every home is different, so ask the company you talk to about pricing and what’s included. Published by Beehive Removal · Updated September 11, 2026 · How we write these guides