Crab Spiders use stealth to hunt and do not build a web.  Like some kind of "alien" being they have 8 eyes lined up on the top of their heads. Eyesight is important if you need to find your prey  by stealth.  They lay in wait for prey, using camouflage to conceal themselves.  This one was sat in the middle of a garden primrose flower, blending in perfectly. Apparently they can change their colour "chameleon" like to match their surroundings.  This is a female and  have seen them in the garden regularly.  Males are quite different and I have yet to find one.