384 THE WORLD OF ANIMAL LIFE 



THE TRAP-DOOR SPIDERS (Family Ctenizid^) 



The home of the Trap-door Spider is very curious and in- 

 teresting. It is made in a hole carefully excavated in the ground. 

 This hole, from one inch to several inches in depth, is neatly 

 lined with silk, and the entrance, which is nearly circular, is closed 

 by a silken pad, which forms the " trap-door ". The spider is 

 always very careful to cover the upper part of this door with 

 fragments of earth, so that, as it exactly fits the entrance, it can 

 hardly be detected when closed, even by the most experienced 

 eye. 



To open this door when the occupant is within is extremely 

 difficult, for, as soon as the spider finds that such an attempt is 

 being made, she runs up to the top of her burrow, and clings with 

 all her strength to the silken pad. When she is out, however, 

 she leaves the door open; and then, by the exercise of a little care, 

 the silken lining can be taken out uninjured from the burrow. 

 After the earth which clings to it has been removed, it looks like 

 a small silken stocking. 



One kind of trap-door spider is even more ingenious, for, 

 besides closing the entrance to her home with a silken pad, she 

 makes a small additional burrow at right angles to the other, a 

 couple of inches or so from the surface of the ground. Into this, 

 the mouth of which is carefully covered with a silken curtain, 

 she retires when threatened by danger, so that, even if the door 

 of the principal burrow be forced open, the dwelling appears to be 

 empty. 



Only one spider of the trap - door group is found in Great 

 Britain. This, however, does not make a true trap-door, but con- 

 tinues the silken lining of the burrow above the surface of the 

 ground, so that the upper part falls over and closes the entrance. 

 This spider is also remarkable for having its eyes set upon little 

 turrets, which project above the level of the rest of the body, and 

 enable it to command a wide field of vision. 



Trap-door spiders very seldom leave their burrows by day, 

 evidently fearing that the open door may attract the notice of 



