They aren't venomous and sit patiently during the day doing nothing at all except pretending they aren't a spider , hence trying to change it's appearance by disguising the number of legs it has and not moving.
At night they spin a web between their front legs and 1 or 2 lines from their vantage point to other points crossing where they expect their prey to move/fly etc. When the prey touches the line/s of web they cast the web over it like a fishing net and bring it back in, it'd be amazing to see it in action!