 Portias hunt in all types of webs , : 491 while other cursorial spiders generally have difficulty moving on webs , and web @-@ building spiders find it difficult to move in webs unlike those they build . : 424 Where the web is sparse , a Portia will use " rotary probing " , in which it moves a free leg around until it meets a thread . : 433 @-@ 434 When hunting in another spider 's web , a Portia ′ s slow , choppy movements and the flaps on its legs make it resemble leaf detritus caught in the web and blown in a breeze . : 514 P. schultzi and some other Portias use breezes and other disturbances as " smokescreens " in which these predators can approach web spiders more quickly , and revert to a more cautious approach when the disturbance disappears . : 313 A few web spiders run far away when they sense the un @-@ rhythmical gait of a Portia entering the web - a reaction Wilcox and Jackson call " Portia panic " . : 418 
