11 EIFE-HISTORY OF BOMWZBUS 17 
The weather improving, the periods of animation 
become more frequent and last longer. Now each 
queen sets to work to search for a nest in which to 
establish her colony. The nest is usually one that 
has been made and afterwards vacated by a field- 
mouse, vole, or other small mammal, and consists of 
fine soft fragments of grass or moss, or it may be 
leaves, woven into a ball with a small cavity in the 
middle. Most of the species choose a nest that is 
under the ground, access to which is obtained by 
a tunnel varying in length from a few inches to a 
yard or more, but generally about two feet. The 
remaining species dwell in nests on the surface of 
the ground hidden in thick grass or under ivy ; 
these are often called “carder-bees” because they 
collect material from around the nest and add it to 
the nest, combing it together with their mandibles 
and legs. But some of the underground-dwelling 
species occasionally occupy nests on or near the 
surface, often in strange situations, such as under 
boxes or in old birds’ nests, rotten stumps, or out- 
houses, while some of the surface-dwelling species 
are sometimes found inhabiting nests under the 
ground, reached by a short tunnel. 
In places where there is much moss or soft dead 
grass the carder-bee queen may sometimes construct 
the entire nest herself. It often happens that the 
mouths of the holes leading to the underground 
nests are overgrown with grass or ivy and half 
closed with debris, consequently they are not easily 
discovered, and the queens of the underground- 
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