42 Insect Architecture. 



a little surprised to see so numerous a colony at tins early 

 season. As the bees had dug a hole in the bank, where 

 they were incessantly entering and reappearing, we were of 

 opinion that they were a peculiar sort of the social earth-bees 

 (Bombi). On approaching the spot, however, we remarked 

 that the bees were not alarmed, and manifested none of the 

 irritation usual in such cases, the consequence of jealous 

 affection for their young. This led us to observe their 

 operations more minutely ; and we soon discovered that on 

 issuing from the hole each bee carried out in its mandibles a 

 piece of clay. Still supposing that they were social earth- 

 bees, we concluded that they were busy excavating a hollow 

 for their nest, and carrying off the refuse to prevent discovery. 

 The mouth of the hole was overhung, and partly concealed, 

 by a large pebble. This we removed, and widened the 

 entrance of the hole, intending to dig down and ascertain 

 the state of the operations ; but we soon found that it was of 

 small depth. The bees, being scared away, began scooping 

 out clay from another hole about a yard distant from the first. 

 Upon our withdrawing a few feet from the first hole, they 

 returned thither in preference, and continued assiduously 

 digging and removing the clay. It became obvious, there- 

 fore, from their thus changing place, that they were not con- 

 structing a nest, but merely quarrying for clay as a building 

 material. By catching one of the bees (Osmia bicornis} 

 when it was loaded with its burden, we ascertained that the 

 clay was not only carefully kneaded, but was also more moist 

 than the mass from which it had been taken. The bee, 

 therefore, in preparing the pellet, which was nearly as large 

 as a garden-pea, had moistened it with its saliva, or some 

 similar fluid, to render it, we may suppose, more tenacious, 

 and better fitted for building. The reason of their digging a 

 hole, instead of taking clay indiscriminately from the bank, 

 appeared to be for the purpose of economizing their saliva, 

 as the weather was dry, and the clay at the surface was 

 parched and hard. It must have been this circumstance 

 which induced them to prefer digging a hole, as it were, in 

 concert, though each of them had to build a separate nest. 



