Ordinarily the ant-eating frog stays beneath the soil surface, in cracks
or holes or beneath rocks. Probably it obtains its food in such
situations, and rarely wanders on the surface. The occasional
individuals found moving about above ground are in most instances
flushed from their shelters by the vibrations of the observer's
footsteps. On numerous occasions I have noticed individuals, startled by
nearby footfalls, dart from cracks or under rocks and scuttle away in
search of other shelter. Such behavior suggests that digging predators
may be important natural enemies. The gait is a combination of running
and short hops that are usually only an inch or two in length. The flat
pointed head seems to be in contact with the ground or very near to it
as the animal moves about rapidly and erratically. The frog has a
proclivity for squeezing into holes and cracks, or beneath objects on
the ground. The burst of activity by one that is startled lasts for only
a few seconds. Then the frog stops abruptly, usually concealed wholly or
in part by some object. Having stopped it tends to rely on concealment
for protection and may allow close approach before it flushes again.
Less frequently, undisturbed individuals have been seen wandering on the
soil surface. Such wandering occurs chiefly at night. Diurnal wandering
may occur in relatively cool weather when night temperatures are too low
for the frogs to be active. Wandering above ground is limited to times
when the soil and vegetation are wet, mainly during heavy rains and
immediately afterward.
Pitfalls made from gallon cans buried in the ground with tops open and
flush with the soil surface were installed in 1949 in several places
along hilltop rock outcrops where the frogs were abundant. The number of
frogs caught from day to day under varying weather-conditions provided
evidence as to the factors controlling surface activity. After nights of
unusually heavy rainfall, a dozen frogs, or even several dozen, might be
found in each of the more productive pitfalls. A few more might be
caught on the following night, and occasional stragglers as long as the
soil remained damp with heavy dew. Activity is greatest on hot summer
nights. Below 20 deg. C. there is little surface activity but individuals
that had body temperatures as low as 16 deg. C. have been found moving
about.
Frogs uncovered in their hiding places beneath flat rocks often remained
motionless depending on concealment for protection, but if further
disturbed, they made off with the running and hopping gait already
described. Although they were not swift, they were elusive because of
their sudden changes of direction and the ease with which they found
shelter. When actually grasped, a frog would struggle only momentarily,
then would become limp with its legs extended. The viscous dermal
secretions copiously produced by a frog being handled made the animal so
slippery that after a few seconds it might slide from the captor's
grasp, and always was quick to escape when such an opportunity was
presented.