How to prevent spiders from entering the house?
How to prevent spiders from entering the house?
Preventing spiders from entering requires two approaches: blocking entry routes and reducing food sources that attract them. Spiders are most likely to enter homes in autumn and winter (October-November) as outdoor temperatures drop and they seek warm places to overwinter.
Seal entry routes
- Door and window sealing — check screens for tears; ensure the gap under doors is less than 5 mm; install weather stripping if necessary.
- Wall cracks — seal cracks in corners, air conditioner pipe entries, and wire openings with expanding foam or cement.
- Ventilation openings — install fine mesh over exhaust fans, air conditioner pipes, and ground-level vents.
Reduce attractants
Spiders enter homes because there is food — other small flying insects. Reducing flying insects will naturally keep spiders away:
- Install bug zappers or sticky flying insect traps.
- Keep kitchen countertops clean; clean up food residues promptly.
- Dispose of garbage daily, especially kitchen waste.
- Check if potted plants are breeding small flies (e.g., fungus gnats).
- Minimize opening windows at dusk when flying insects are most active.
Outdoor lighting management
- Replace outdoor lights with warm-yellow lights (sodium lamps), which are far less attractive to flying insects than white lights (mercury lamps).
- Do not leave porch lights on all night; use motion-sensor lights instead.
- Bright lights outside windows attract flying insects to the window, and spiders follow.
Chemical prevention
Spray deltamethrin-containing household insecticide on window frames, door frames, corners, and baseboards. Once dry, it forms a film; spiders that crawl over it are poisoned. Combined with physical prevention measures, the effect is better.