Arachnid surge unfolding this Autumn: Understanding the potential spike in spider population activity
In the UK, the unusually hot summer of 2025 has brought about a small boom in insect populations, providing a bountiful food source for our uninvited indoor guests - house spiders. This year, the late summer and fall have seen an increase in house spider sightings, with spiders such as those from the groups Tegenaria and Eratigena becoming more active.
According to Dr David Gee, a zoology lecturer at the University of Derby, this increased activity is due to the successful early growing season. As the adult male spiders seek out mates, they become more noticeable, leading to a 'turf war' in homes as they compete for territory.
Despite their increased presence, house spiders play an important role in controlling pests like flies and mosquitoes. However, it's important to note that only approximately 25 out of 50,000 known spider species have venom capable of causing illness in humans. Most house spiders are harmless and unlikely to bother people.
In certain parts of the world, the fall period when spiders become more noticeable as they seek warm, dry places indoors is known as 'Spider Season.' In Tennessee, for example, this term could refer to the increased activity of species like the brown recluse, which poses health risks.
Arachnologists have found that natural deterrents, such as lemon oil, peppermint oil, and horse chestnuts (aka conkers), have weak or inconsistent evidence supporting their effectiveness in keeping homes free of house spiders.
As we move into the summer of 2026, parts of the US are experiencing hot and humid conditions, creating favourable conditions for active arachnids. With more food and better conditions to survive and thrive, it's likely that we'll continue to see an increase in house spider sightings.
In conclusion, while the increased activity of house spiders may be a nuisance for some, it's important to remember that they play a crucial role in controlling pests and pose little threat to humans. By understanding their behaviour and learning to coexist with them, we can minimize any disruptions they may cause in our homes.
