How Well Do Spiders Walk Upside Down?
WouterDespite the fact that the majority of land animals evolved to rely on the ground for movement, many spider species turn the world upside down. Several of these odd creatures have even developed ingenious hunting methods.
Spiders are known to ‘walk’ on smooth surfaces, but how well do they actually walk? Scientists recently investigated this peculiar lifestyle by studying over one hundred different species of spider. The results of the study have shown that the spiders of the world are not all created equal.
In particular, researchers focused on the spider’s ability to traverse vertical surfaces. In this regard, spiders use hairs to stick to a variety of surfaces. They also possess tiny bristles on the ends of their legs that are used to grip the surfaces.
Aside from the ability to stick to a variety of surfaces, spiders can also traverse wet surfaces. This is made possible by the spider’s ability to secrete a sticky adhesive substance from its feet.
Using this adhesive, the spider can create a force of up to 0.025 Newtons when it is in contact with a smooth surface. These forces are strong enough to carry 170 times the body weight of a human.
Although there are a handful of spiders known to ‘walk’ on the ground, the majority of these creatures spend their lives hanging from a web. The upside-down hanging position confers a high energy efficiency. The shape of the upside-down hanging spider enables it to move faster, while also bridging.
