California Pest Calendar: What to Inspect & Seal Every Season

As the weather warms up, insects rapidly expand their colonies and begin actively searching for food.

• The Swarmer Check: Spring is when reproductive termites (swarmers) fly out to start new colonies. Walk the perimeter of your house looking for discarded, translucent wings on your window sills or spider webs. If you see them, you need a professional termite inspection immediately.
• Pre-Bait the Ants: Argentine ants wake up hungry. Do not wait for them to enter your kitchen. Place liquid borax bait stations in your flower beds to kill the scouts before they map a trail into your house.
• Clear the Defensible Space: Trim all tree branches and shrubs so they are at least 18 inches away from your roof and exterior walls. Branches act as a “pest highway” for ants and roof rats to bypass your perimeter ground treatments.

During the intense, dry heat of a California summer, the pests outside are dying of thirst. Your air-conditioned, plumbing-filled home is an oasis.

• Moisture Lockdown: Check under every sink for slow drips. Cockroaches will invade your home seeking the condensation on your pipes. Wipe sinks dry at night.
• Flea Prevention: The dry heat causes flea populations in sandy soils to explode. Keep your lawn mowed short to let UV sunlight bake and sterilize the soil, and maintain your pet’s preventative medications.
• Trash Management: Hot garbage ferments incredibly fast, drawing flies, wasps, and raccoons. Wash out your exterior municipal bins with a hose and a cap of bleach once a month.

As nighttime temperatures begin to drop and the threat of winter rain approaches, rodents frantically search for warm, dry shelter to build their winter nests.

• The Pencil Test: A house mouse can fit through a hole the size of a standard #2 pencil. Walk your foundation and look for gaps around your HVAC lines, dryer vents, and plumbing penetrations.
• Stuff and Seal: Do not use expanding foam to seal holes (rats chew right through it). Stuff the gaps tightly with copper mesh or steel wool, and then caulk over the metal to lock it in place.
• Check Door Sweeps: If you can see daylight under your exterior doors or garage door, rodents can get in. Replace worn weatherstripping and install heavy-duty, bristle-style door sweeps.

California atmospheric rivers saturate the soil. This forces ground-dwelling pests up and out of the flooded dirt and into your dry walls.

• Check Drainage: Ensure your gutters are completely clear of leaves and that your downspouts discharge water at least 5 feet away from your foundation. Standing water against your slab is the #1 cause of Subterranean Termite infestations.
• Attic Inspection: Go into your attic on a sunny day, turn off your flashlight, and look for tiny pinholes of daylight shining through the roof. These small leaks cause wood rot, which eventually attracts Carpenter Ants.
• Firewood Safety: Never stack firewood directly against your house or keep it inside. Black Widows and termites love damp woodpiles. Keep it elevated and 20 feet from your exterior walls.