Ogre-Faced Spiders Can Hear Without Ears

The spider seen in the image below is called the ogre-faced spider. They are believed to have the largest eyes of any known spider species, and one of their hallmarks is the ability to see in the dark 2000 times better than humans. It turns out incredible eyesight isn't the only thing that these spiders have going for them.

New research shows that the ogre-faced spider is also able to hear without having ears. The spiders can hear both low and high-frequency sounds using receptors in their legs. Researchers say they can detect sounds from at least 6.5 feet from the source of the sound. They are sensitive to frequencies up to 10 kilohertz.

The scientists used both laboratory tests and field observations in their study. They were able to show that auditory stimuli in the same low-frequency range as the wing beats of the moth, mosquito, and flies prompt spiders to perform a backward strike. The backward strike is one of the signature hunting moves of the spider. This led researchers to determine that the spiders use auditory clues to detect and capture flying prey.

Study co-author Jay Strafstrom says the spiders are a "gold mine" of information. The observations performed in the study shows that not only does the spider possess incredible visual capability, they can hear very well. Ogre-faced spiders are tropical in nature and found worldwide, including in the States, particularly in Florida.

The spiders are nocturnal and spend the daytime hiding among plant fronds. During the day, the creature tends to play dead and hunts and kills prey at night. The spiders strike forward to capture prey below them and strike backward to capture prey flying above them, and the study found that the hunting methods rely on different senses.