350 THE INSECT WORLD. 
—for men, horses, dogs, and animals of all kinds know perfectly 
well the danger to which they expose themselves by approaching 
too near to a hive in full operation,*—the bee gets a reinforcement 
and very soon returns to the combat with a determined battalion. 
All this is, it seems to us, intelligence. 
We have just said that there are sentinels at the entrance of 
every hive. They touch with their antennz each individual that 
wishes to penetrate into the house. Hornets, the Death’s-head 
Sphinx, slugs, &c., often try to introduce themselves into the hive. 
In that case, on the appeal of the watchful porters, all the bees 
combine their efforts to defend the entrance to their habitation. 
It would be impossible for them, in fact, to stop the ravages of 
their enemies when once entered into the interior. When a 
sphinx has succeeded in introducing itself into a hive, it sits down 
and drinks the honey in great bumpers, devouring all the pro- 
visions: and the unfortunate proprietors of the house are obliged 
to emigrate. To stop the entrance of moths which fly by night, 
the bees contract, and sometimes barricade, their door with a 
mixture of wax and propolis, When a slug or any other large 
animal has managed to introduce itself into the interior, they kill 
it and wrap it up in a shroud of propolis, as we have already 
related. 
However, they are quite helpless against certain microscopic 
parasites which sometimes attack them. The bee-louse, which 
has been described and drawn by Réaumur in one of his Memoirs,t 
and the parasite which was described in 1866 by M. Duchemin, 
the Sugar Acarus, which is found in the liquid honey of 
those hives which are attacked by the disease called the rot 
(pourriture), are the most serious enemies of the bee. The 
Gallerias are also terrible enemies to them. Every hive thus 
attacked is ruined. These destructive insects attack also the wild 
bees, drive them from their nests, and destroy the wax of the 
cakes forming the comb. The Gadlerta impudently makes his 
home in the houses of bees, wild as well as domesticated. 
* The bee’s sting may lead to very serious consequences. It often happens that 
large animals, such as horses or oxen, tied up in the neighbourhood of a bee-hive, 
and which have disturbed the bees, die in consequence of stings received from 
them. 
+ Tome v., planche 36, 
