532 
THE STUDY OF INSECTS . 
Fig. 640. 
Family STAPHYLINID^: (Staph-y-lin'i-dae). 
The Rove-beetles. 
The rove-beetles are very common about decaying ani¬ 
mal matter, and are often found upon the ground, under 
stones or other objects. They are mostly very small insects; 
a few species, however, are of larger size, measuring a half 
inch or more in length. Their appearance is very charac¬ 
teristic, the body being long and slender, and the wing- 
covers very short (Fig. 640). The wings, however, 
are fully developed, often exceeding the abdomen 
in length ; when not in use the wings are folded 
beneath the short wing-covers. The abdominal 
segments are freely movable, and arc seven or eight 
in number. 
It is interesting to watch one of these insects 
fold its wings; frequently they find it necessary 
to make use of the tip of the abdomen or of one of the legs 
in order to get the wings folded beneath the wing-covers. 
The rove-beetles can run quite swiftly; and they have 
the curious habit, when disturbed, of raising the tip of the 
abdomen in a threatening manner, as if they could sting. 
As some of the larger species resemble wasps somewhat in 
the form of the body, these threatening motions are often 
as effective as if the creature really had a sting. 
As these insects feed upon decaying animal and vegetable 
matter, they should be classed as beneficial. The larvae re¬ 
semble the adults in the form of the body and are found in 
similar situations. 
About one thousand North American species of rove- 
beetles have been described. The great majority of them 
are small and exceedingly difficult to determine, Among 
the large species that are common are the following:— 
Creophilus villosus (Cre-oph'i-lus vil-lo'sus).—This species 
varies from one-half inch to nearly an inch in length. It is 
of a shining black color, spotted with patches of fine gray 
