It's retarded. It scratches up the wall then makes itself invisible and hides it's heat signature.
They stand around wondering where it is and assume it has climbed over an enormous wall without anyone noticing.
Rather that call the control room straight away to ask what the tracking beacon says the ginger bitch decides to car for a car ride and call them on the way.
As she's off doing this they stroll in to the cage to check out the pretty scratch marks on the wall only to get a call from her telling them it's still in there.