Why do we find spiders scary?
In a well-known UK study, 75 per cent of respondents reported at least a mild fear of spiders. Arachnophobia can run in families, but where did it start?
One theory is that the exaggerated fear stems from our evolutionary past when spiders were more of a threat. However, recent research has shown the reaction may actually be a combination of fear and ‘core disgust’ – an instinctive, reflex avoidance of whatever is bad for us, especially things that spread disease. Cockroaches, maggots and corpses elicit a similar response, but the fast scuttling and venom of spiders ramps up the fear factor. Yet arachnophobia is more common in Europe than in Africa or Australia, home to more deadly spiders, which shows there may be strong cultural influences.
To put your mind at rest, of the 43,000 spider species known, fewer than 30 are implicated in human deaths.
I t is 60 years since Jane Goodall watched a chimpanzee fish for termites, and the number of species known to use tools has steadily grown. But, so far, tool use has been seen in few insects. Female Ammophila wasps may pick up a small stone to pat down the earth sealing their burrow, which contains the paralysed caterpillar that nourishes their parasitic larva.
Ants also use tools. For example, the Mediterranean species Aphaenogaster subterranea drops bits of leaf into rotting fruit or carcasses, then carries the foodsoaked debris back to its nest.
In India, male Oecanthus tree crickets cut holes in leaves to create sound controllers, or baffles, which amplify their songs twofold. Now a new study has discovered that smaller, quieter individuals are more likely to resort to these leafy megaphones. Ben Hoare