The original sentence is:
"Tarantulas use their webs to hunt, make tunnels and protect their eggs."
This sentence is almost correct, but to improve clarity and correct grammar, especially in listing multiple actions, it's best to include a comma before the last item in the list (this is called the Oxford comma).
So, the corrected sentence should be:
"Tarantulas use their webs to hunt, make tunnels, and protect their eggs."
Adding the comma after "make tunnels" makes it clear that the list contains three separate actions.