Spiders are known for their unique survival tactics, and playing dead—also called thanatosis—is one of them. Here are four reasons why spiders use this defense mechanism:
Avoiding Predators
Many spiders play dead to escape predators such as birds, lizards, and other insects. By remaining motionless, they become less noticeable or unappealing to predators that prefer live prey.
https://safepestsol.com/why-spiders-play-dead/