120 THE HUMBLE-BEE 



difficulty in obtaining access to the holes from the 

 inside, and to this defect, which was afterwards put 

 right by filling the inside of the lid with clay, I owed 

 the loss of three mothers of families. No brood was 

 injured or destroyed in the nests protected by these 

 mouse excluders, but by the time they were placed 

 in position most of the nests had almost passed 

 through the period of danger, for I have never seen 

 a nest containing workers injured by a mouse. 



No doubt there are other animals that may 

 destroy the brood of the humble-bee. Slugs and 

 millipedes are vegetable feeders, and I have no 

 evidence that they did any direct harm to the brood 

 in my nests ; indeed, I think they never entered the 

 nests as long as the latter remained fairly dry. 

 But the common centipede {Lithobius) I regarded 

 with considerable suspicion, for it is carnivorous, 

 and also very active. Several times I found these 

 centipedes in the cavities containing nests occupied 

 by my queens, and once I saw one biting some 

 cocoons I had lifted out of a deserted nest and had 

 left lying on the ground for half an hour. 



To the above causes of loss I must regretfully 

 add another my own blundering. 



It has been mentioned that the queens are liable 

 to forsake their nests if they are disturbed in them, 

 and that very little interference causes a queen to 

 desert her brood when it is young, but that after 

 the cocoons are spun she becomes more attached to 

 it, and when the workers are about to emerge only 

 a severe fright will cause her to abandon it. A 



