  It is argued that in the context of TeV gravity with large extra dimensions,
excited string states produced in colliders and in the interaction of cosmic
rays with the atmosphere may decay preferentially into invisible bulk modes,
rather than visible gauge fields on the brane. This contrast to the black hole
case comes about because of the absence of a relationship between physical size
and temperature for string ball states. We estimate the effect of this upon the
number of events predicted at cosmic ray observatories and colliders.
