Australians are being warned that squashing a spider not only leaves an unsightly mess, it could also be hazardous to people's health. In what many animal-lovers will surely see as a case of poetic justice, doctors are warning that if the contents of a splattered spider's stomach come into contact with sensitive parts of the human anatomy they will cause severe pain and swelling. That is because some Australian species' intestines contain powerful enzymes that destroy human tissue. One man was reported to have sustained pain and swelling around his eyes when he smashed a huntsman spider with a hammer and the remains of the animal squirted into his face. In another case, a fragment of a widow spider landed in a woman's eye after she swatted it, leading to redness and acute pain. Writing in the Medical Journal of Australia, Geoffery Isbister, of Mater Hospital in Newcastle, New South Wales, reported two cases of people using their bare hands to squash daddy long legs and then wiping their eyes. Both had to be treated in hospital for swelling, itchiness and blurred vision. Daddy long legs spiders are not normally considered dangerous because their lanky frames and tiny bodies mean it is anatomically difficult for them to bite a human. Dr Isbister said children in particular should refrain from squashing spiders, as there was a greater likelihood they would rub their eyes without first washing their hands. The New South Wales Poison Information Centre received five calls last year concerning spider-related eye injuries and four calls in 1999. Doctors suspect there may be other cases of eye injury that have not come to light because people experiencing such symptoms after spider encounters 'did not put two and two together'. Of 100,000 calls to the information centre last year, 5,000 were about spider bites - a reflection of the fact that Australia is home to some of the world's most dangerous spiders. The Sydney funnel-web spider, for instance, is recognised as the world's deadliest. They can be very aggressive when disturbed, rearing up on their hind legs and baring an impressive set of fangs. A bite produces severe pain, leading to sweating, muscle tremors and cramp. Unless anti-venom is administered quickly, the victim will lapse into a coma and may die. Other dangerous species are the chunky-bodied mouse spider, and the red-back spider, which has a fondness for lurking under toilet seats and in other nooks and crannies around the house.