Spider webs have existed for at least 100 million years, as witnessed in a rare find of Early Cretaceous amber from Sussex, in southern England. Many spiders build webs specifically to trap and catch insects to eat. However, not all spiders catch their prey in webs, and some do not build webs at all. Spider web is typically used to refer to a web that is apparently still in use , whereas cobweb refers to abandoned (i.e. dusty) webs.