Question

How can spiders tell when something is trapped in their web?

Answer 1

they might have a sense or as the insect moves to get out the web so this moves the web so the spider realizes this 

Answer 2

Answer:

The darknet is also used for illegal activity such as illegal trade, forums, and media exchange for pedophiles and terrorists. At the same time traditional websites have created alternative accessibility for the Tor browser in efforts to connect with their users.