Pest exterminators are being kept busy with an influx of white-tailed spiders in Auckland.
The summer months bring increased numbers of the spider, whose bite can cause a nasty rash and swelling.
And according to ACC figures, around 300 people a year seek medical help for white-tail spider bites, at a cost of $65,000 to $80,000.
Bug King owner Mark McDonald was getting 10 calls a week about white-tailed spider infestations, mainly from West Auckland.
Pest experts say white-tailed spiders usually live outside, in roof spaces or beneath floors, but will move inside if their habitat has been disturbed, through gardening, bad weather or if there is a lack of food.
White-tailed spiders feast on other spiders, so experts recommend keeping your house free of spider webs to keep numbers down.
"If there's a fight between a white-tail and a daddy long legs, it's 50-50 who's going to win," said McDonald.
"The white-tail has the venom, but the daddy long legs has the speed.
"If the white-tail gets a bite in, the daddy long legs has had it."
A New Zealand Pest Control spokeswoman said it was getting several calls a week from people concerned about white-tail spiders at their properties, mainly in Titirangi, Swanson and Glendowie.
"Naturally, spiders like hedgey, bushy areas. It's environment rather than suburb," she said.
"With white-tails, it's not a good idea to leave clothes on the floor because they like to hide in them."
According to the Ministry of Health, the white-tailed spider causes a painful, burning feeling, swelling, redness and itchiness. There are usually no long-lasting effects. ACC says it mainly receives claims where there has been an allergic reaction to the bite, or someone has developed an infection as a result of the bite.
This month the Herald on Sunday revealed ACC had paid $2,087,890 after 28,093 claims involving insect-related injuries - including spider bites - over the past two years.