Mimicry and Warning Colours in Grasshoppers, 125 
travelling, move so slowly tliat the laziest snail 
might easily overtake and pass one o£ their bands, 
and even disappear beyond their limited horizon in 
a very short time. 
They often select an exposed weed to feed on, 
clustering together on its summit above the sur- 
rounding verdure, an exceedingly conspicuous 
object to every eye in the neighbourhood. They 
also frequently change their feeding-ground ; at such 
times they deliberately cross wide roads and other 
open spaces, barren of grass, where, moving so 
slowly that they scarcely seem to move at all, they 
look at a distance like a piece of black velvet lying 
on the ground. Thus in every imaginable way 
they expose themselves and invite attack ; yet, in 
spite of it all, I have never detected birds preying 
on them, and I have sometimes kept one of these 
black societies under observation near my house 
for several days, watching them at intervals, in 
places where the trees overhead were the resort of 
Icterine and tyrant birds, Guira cuckoos, and other 
species, all great hunters after grasshoppers. A 
young grasshopper is, moreover, a morsel that 
seldom comes amiss to any bird, whether insect or 
seed eater; and, as a rule, it is extremely shy, 
nimble, and inconspicuous. It seems clear that, 
although the young Zoniopoda does not mimic in 
its form any black protected insect, it nevertheless 
owes its safety to its blackness, together with the 
habit it possesses of exposing itself in so open and 
bold a manner. Blackness is so common in large 
protected insects, as, for instance, in the un- 
palatable leaf-cutting ants, scorpions, rnygale 
