The one you see above has made a pretty extensive web over the myrtle vines. In the center of the web it has constructed this tunnel where it hides. I assume when something lands on its web it quickly scrambles out to kill it.
This is a fairly large spider that was devouring something that was tangled in its web. When it saw me approach it scrambled up to safety near a beam on the carport. When I walked away it came back down to do more eating. I approached more slowly the next time and got the shot. With its legs extended this spider was probably an inch (30cm) long.