66 INSECTS MIMICKING ANTS. 
fianks of the main army, and re-enter it again after 
their task is accomplished. If some very rich place be 
encountered anywhere near the line of march—for 
example, a mass of rotten wood abounding in insect 
larve, a delay takes place, and a very strong force of 
ants is concentrated upon it.’ 
Belt, also, has given! an excellent account of these 
Ecitons. He observed that spiders were peculiarly 
intelligent in escaping them, making off several yards 
in advance ; and not like cockroaches and other stupider 
insects, taking shelter in the first hiding-place, where 
they were almost sure to be detected. The only chance 
of safety was either to run right away or to stand still. 
He once saw a Harvestman (Phalangium) standing 
in the midst of an army of ants with the greatest 
cireumspection and coolness, lifting its long legs one 
after the other. Sometimes as many as five out of 
the eight would be in the air at once, but it always 
found three or four spots free from ants, on which it 
could safely place its feet. On another occasion, Belt 
observed a green leaf-like locust, which remained per- 
fectly still, allowing the ants to run over it. This 
they did, but seem to have been quite deceived by its 
appearance and immobility, apparently taking it for a 
leaf. 
In other cases, insects mimic ants, and thus escape 
attack or are able to stalk their prey. Belt mentions 
a spider which in its form, colour, and movements so 
1 The Naturalist in Nicaragua, p. 17, 
