216 



MEANS OF DEFENCE OF INSECTS. 



I am now to lay before you some examples of the- con- 

 trivances, requiring skill and ingenuity, by which our busy 

 animals occasionally defend themselves from the designs and 

 attack of their foes. Of these I have already detailed to 

 you many instances, which I shall not here repeat; my 

 history therefore vvdll not be very prolix. I observed in my 

 account of the societies of wasps, that they place sentinels 

 at the mouth of their nests. The same precaution is taken 

 by the hive-bees, particularly in the night, when they may 

 expect that the great destroyers of their combs, Galleria 

 mellonella and its associates, will endeavour to make their 

 way into the hive. Observe them by moonlight, and you 

 will see the sentinels pacing about with their antennae 

 extended, and alternately directed to the right and left. In 

 the mean time the moths nutter round the entrance ; and it 

 is curious to see with what art they know how to profit of 

 the disadvantage that the bees, which cannot discern objects 

 but in a strong light, labour under at that time. But should 

 they touch a moth with these organs of nice sensation, it falls 

 an immediate victim to their just anger. The moth, how- 

 ever, seeks to glide betw een the sentinels, avoiding with the 

 utmost caution, as if she were sensible that her safety 

 depended upon it, all contact with their antenna?. These 

 bees upon guard in the night are frequently heard to utter a 

 very short low hum ; but no sooner does any strange insect 

 or enemy touch their antennae than the guard is put into a 

 commotion, and the hum becomes louder, resembling that of 

 bees when they fly, and the enemy is assailed by workers 

 from the interior of the hive. 1 



To defend themselves from the death's-head hawk-moth, 

 they have recourse to a different proceeding. In seasons in 

 which they are annoyed by this animal, they often barricade 

 the entrance of their hive by a thick wall made of wax and 

 propolis. This wall is built immediately behind and some- 

 times in the gateway, which it entirely stops up; but it is 

 itself pierced with an opening or two sufficient for the passage 

 of one or two workers. These fortifications are occasionally 



1 Huber, Nouv. Obs. ii. 412. 



