 However, a "Portia" takes a relatively long time to see objects, possibly because getting a good image out of such tiny eyes is a complex process and needs a lot of scanning.This makes a "Portia" vulnerable to much larger predators such as birds, frogs and mantises, which a "Portia" often cannot identify because of the other predator's size.Spiders, like other arthropods, have sensors, often modified setae (bristles), for smell, taste, touch and vibration protruding through their cuticle ("skin").