A school has been forced to close because of an outbreak of Britain's most venomous spider.
The Dean Academy, in the Forest of Dean, said it "had identified an issue with false widow spiders" in its ICT block and other areas of the site.
A letter from vice-principal Craig Burns to parents said the school would be shut on Wednesday to be fumigated.
Conservationists believe a change in the climate could be the cause of an increase in sightings of the species.
'No bite reports'
In the letter, Mr Burns said the school had taken immediate pest control advice on discovery of the spiders.
Initially the decision was taken to close the ICT block but further discoveries of the species elsewhere have led to a full school closure.
"This will enable pest control to fumigate every area in the academy and ensure everyone's health and safety," Mr Burns wrote.
"There have been no reports of anyone being bitten by the false widow spiders at the academy but if you have any concerns please seek medical advice."
The school is expected to be open as normal on Thursday.
The false widow (Steatoda nobilis) is about the size of a 50p coin and is the most dangerous of the 12 species of biting spider known in Britain.
There have been no reported deaths from its bite in the UK.
Symptoms can include severe swelling, chest pains and tingling of fingers, with the severity depending on the amount of venom injected.
Gloucestershire spider recorder David Haigh said people would have to be "very unlucky" to be bitten by one as they do not move very quickly and are not aggressive.
He said he has never heard of a school being closed due to spiders, but said recent media attention on the False Widow has led to greater awareness.