Residents in London are being told to beware the white-haired caterpillars that can cause rashes, vomiting and asthma attacks. The British Forestry Commission says caterpillars that become oak processionary moths have been spotted in and around the British capital since mid-April. The caterpillars are covered in thousands of hairs containing the protein thaumetopoein, which can cause skin rashes, sore throats, breathing difficulties and eye problems. People are being warned not to touch the creatures, which are most often found in oak trees – and to keep pets away from them, too. Officials are treating oak trees with pesticide to try and eliminate the moths, which were accidentally introduced to Britain in 2005 on plants imported from continental Europe. The Observer newspaper said on Sunday that authorities will also set traps for the caterpillars. According to The Telegraph , the Forestry Commission is also taking the unprecedented step of having helicopters spray woodland areas with insecticide.