Spraying diluted peppermint oil around windowsills, doorframes and skirting boards is an effective, non-toxic way to keep large spiders out of homes during October, according to Adam Juson, co-founder and director of commercial pest control specialists Merlin Environmental.
October is the peak of spider mating season, and by autumn spiders have finished growing and reached their full adult size, making them particularly large. With sudden rain and falling temperatures, spiders are looking for somewhere warm, sheltered and undisturbed, while males are searching for mates.
Seal gaps and use peppermint oil
Juson explained that harsh chemicals or expensive treatments are not needed to keep spiders at bay, as a few simple changes will do. First, it is a good idea to seal any gaps, as spiders can squeeze through surprisingly tiny openings.
He said: "Take a look for gaps and cracks around window frames, underneath doors and anywhere pipes or cables enter your home. Sealing them will have more impact than anything else."
Peppermint oil is another option for making a home less attractive to spiders. "Regularly spraying diluted peppermint oil around windowsills, doorframes and skirting boards actually works," Adam added. "And it’s non-toxic, so it’s better for you and your home."
How to make and apply the spray
Peppermint oil acts as a natural deterrent because its strong menthol and monoterpene compounds overwhelm spiders' sensitive sensory and smell organs located on their legs. It should be diluted before use and applied regularly to ensure it continues to work.
Combine one cup of water with 15 to 20 drops of pure peppermint essential oil, optionally adding a splash of liquid dish soap. Pour the mixture into a spray bottle and mist windowsills, door frames, skirting boards, dark corners and cracks where pests might enter. Alternatively, put a few drops of pure oil onto cotton balls and tuck them into tight spaces or corners. It is best not used around cats and dogs.
Reduce food sources and hiding spots
Juson explained: "Spiders also come indoors looking for food. So, if you have flies, moths and other small insects around, spiders will follow them in."
Keeping bins tidy, using window screens and removing any standing water are good ways to make a home less attractive to insects. Removing garden lights from near doors and windows can also help. Regular vacuuming can make a difference too.
He said: "Spiders search for mates by following silk trails. The more regularly you vacuum, the fewer trails they have to follow. Prevention always beats chemicals. So, do what you can to make your home less appealing to spiders, rather than finding ways to tackle them once they’re in."
