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Psyche 
[Vol. 87 
analysis of the signal was attempted due to the high signal-to-noise 
ratio. We were unable to detect any airborne component to this 
stridulatory vibration. Workers restrained by having an antenna 
clamped in forceps responded in the same manner as those re¬ 
strained with glue. Similarly, when a worker was engaged in 
apparent stridulatory movements, a vibratory signal of the type 
described above was recorded from the substrate. Thus, the vibra¬ 
tory signal produced by a L. muscorum worker is readily trans¬ 
mitted to the substrate through its legs. 
** lip. . . 
■ mu ' .. m u 
0.25 sec. 
Fig. 3. Sonogram of the substrate-borne vibratory signal produced by a stridulat- 
ing L. muscorum worker. 
3. Context 
A. Restrained 
L. muscorum workers will stridulate when they are restrained. 
Such restraint can be imposed by glue or forceps, and occasionally 
occurred in laboratory colonies when an ant became trapped under 
the lid of its nest or foraging dish. It has been suggested that similar 
situations might arise in nature as the result of nest cave-ins, or 
fighting (Markl, 1965; Spangler, 1967). 
B. Fighting 
L. muscorum workers are often aggressive to alien conspecifics, 
and will bite, pull and dismember such aliens during prolonged 
fights (Stuart, 1978). Stridulation is characteristic of these fights and 
is displayed not only by workers which are being held or pinioned 
by their opponents, but also by those workers which are holding or 
pinioning their opponents. Stridulation in the former situation may 
be analogous to that displayed by restrained ants, but in the latter 
situation occurs in quite a different behavioral context. Adult alien 
conspecifics are dismembered and killed but are not eaten (Stuart, 
1978), and therefore this context differs from feeding. 
