Why Can Spiders Walk on Water?
WouterIf you’ve ever been to the beach or a lake, you may have wondered why some spiders walk on water. While spiders that can swim have the ability to move through the water without breaking surface tension, they don’t actually walk on water. Instead, they use a technique that’s similar to a rowboat’s.
In order to keep their legs dry, aquatic spiders will often use spindly legs that allow them to balance on water. They can also pounce on prey that’s in the water. Fishing spiders, for instance, have legs that are hydrophobic, meaning that they don’t absorb the moisture from the water.
These legs aren’t always wet; fisher spiders often have a waxy layer that repels water. This allows them to stay on top of the water while walking or galloping.
Spiders aren’t very good swimmers, though. Unlike fisher spiders, they don’t have webs to hold onto. The way they move on the water is by using a technique called “dimples.” Dimples are made on the water’s surface, which create drag. This drag provides resistance to propel the spider forward.
Some spiders have eight legs, while others have just two. Those with jumping abilities will have a pair of claws on each leg. These claws help the spider grip surfaces in the water. They also trap air, allowing the spider to breathe underwater.
There are a variety of different species that can walk on water. Some, such as the six-spotted fishing spider, have the ability to swim and catch prey. Some, such as a tarantula, don’t even have webs.
