The research comes from Cornell University. The finding came about with the aid of a 3D printed device that helped to hold the spiders in place during the course of the experiments. By holding the spiders in the specially created device, the researchers were able to implant micro-electrodes into the brain of a spider. The researchers found, when studying brain activity of the jumping spider, that the spiders were not only reacting to visual stimuli, but also the voices of the scientists in the room.
The electrodes enabled the researchers to visualize brain activity. They noted how the spider responded to objects placed within its field of vision and also to sounds within a radius of three meters. Speaking with the website 3ders, Professor Ron Hoy, who co-led the research, said: “We are the first and only lab that has successfully and fully been able to tap into what the spider’s brain is listening to.”
Further research showed that the spiders tended to respond to sounds within a close range of 80 to 130 Hz. This frequency range — 90 Hz specifically — is about the same frequency as a parasitic wasp’s wing beat, and wasps prey on the jumping spiders. By being able to hear, the spider has a chance of avoiding the predatory wasp.
As to how the spiders hear, they don’t use their ears. Spiders listen with the hairs on their legs, also known as trichobothria hairs. Trichobothria are present in most orders of the Arachnida.
Further details of the research are outlined in the following video:
The findings are published in the journal Current Biology. The research is titled “Airborne acoustic perception by a jumping spider.”
In related news, Oxford University researchers have found that some species of spider tune their webs to different frequencies in order to catch prey and to attract partners, according to a new study. Keeping with the spider theme, a new study has shown how tarantulas molt in order to grow larger and repair damage, with the whole process taking anything from 15 minutes to several hours. This has been captured in an interesting time-lapse video:
