nS THE HUMBLE-BEE 



eventually disappearing without having harmed the 

 bees. 



Several more of my nests came to grief through 

 a sudden and mysterious destruction of the brood. 

 In three or four instances the brood was in an 

 advanced stage, within a few days of the emergence 

 of the workers. The cocoons were torn open, and 

 the fragments were scattered about the nest, which 

 was in a state of great disorder. I never succeeded 

 in catching the assailants at work, but I set traps in 

 two of the nests the day after the cocoons had been 

 rifled, baiting them with the empty cocoons, and 

 caught shrews which I have no doubt were the 

 culprits, as these animals are insectivorous, and 

 the brood of a humble-bee would make a dainty 

 meal for them. In another case I found a 

 field-mouse (Mus sylvaticus) occupying a nest from 

 which the cocoons had disappeared. 1 Probably the 

 common house-mouse also eats the brood when it 

 can get a chance. Field voles (Arvicota agrestis), 

 distinguishable from the true mice by their shorter 

 tails, stouter bodies, and smaller eyes and ears, were 

 common in the neighbourhood of my nests, and 

 were sometimes found occupying the empty ones, 

 but there was no evidence that they attacked the 

 brood. Some of the nests had their material added 

 to, others were largely reconstructed, and I think 

 this must have been chiefly the work of voles. 



1 I cannot corroborate Col. Newman's statement, quoted by Darwin, that 

 humble-bees' nests are more numerous near small towns than in the open 

 country, believed to be because the cats in towns keep down the field mice, 

 and think that this must be the case only in particular localities. 



