Observations of the spider’s behavior show that it jumps out of its hiding place if there is a medium-sized fly

Observations of the spider’s behavior show that it jumps out of its hiding place if there is a medium-sized fly in the web; if a small fly comes across, the spider does not pay attention to it. Explain how the spider learns about the size of its prey.

He learns about the size of his victim through the web. Their web is pretty interesting. This substance is very strong and delicate. Some threads contain an adhesive that helps catch insects. The spider knows which threads have no adhesive and moves along them. By the degree of tension of the web, the spider understands the size of the victim. An analogy can be drawn with a fisherman, who understands the approximate size of a fish by the degree of tension on the line on a fishing rod. When a large catch is caught in the web, the spider begins the process of digestion.