266: MEANS OF DEFENCE OF INSECTS. 
repeat; my history therefore will 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 de- 
stroyers of their combs, Tinea mellonella, ¥’. and its as- 
sociates*, will endeavour to make their way into the hive. 
Observe them by moonlight, and you will see the senti- 
nels pacing about with their antennee extended, and al~ 
ternately directed to the right and left. In the mean 
time the moths flutter round the entrance; and it is cu- 
rious to see with what art they know how to profit of 
the disadvantage that the bees, which cannot discern ob- 
jects 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 thejr just anger. 
The moth, however, seeks to glide between the sentinels, 
avoiding with the utmost caution, as if she were sensible 
that her safety depended upon it, all contact with their 
antennz. ‘These bees upon guard in the night, are fre- 
quently heard to utter a very short low hum; but no 
sooner does any strange insect or enemy touch their an- 
tennee, 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 inte- 
rior of the hive. 
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 
2 Vou. i. 4th Ed. 164. > Huber, Nouv. Obs. ii. 412. 
