The venomous false widow spider has infiltrated schools in East London, leaving pupils facing weeks without classroom lessons due to the infestation.
Parents and carers had to collect children after the most dangerous species of spider in the UK were discovered; bites can be painful and lead to swelling but aren't life-threatening.
Newham council's environmental team unearthed the false widow spiders and altered head teachers.
Pest control is expected to take three weeks to clear the creatures from the school in Canning Town, Plaistow and Beckton and are working to remove the infestation before more eggs are laid.
False widow spiders look similar to lethal black widow spiders and are native to the Canary Islands. It's thought the spiders arrived with a shipment of bananas in 1879 in Torquay.
They like living indoors, preferring lavatory blocks and sheds. Its venom can cause muscle pain, cramps and in some circumstances, palpitations.