That sound is one of the few that could get Nepeta to stop in her tracks. She knows quite well that hissbeasts can be dangerous and given the nature of the Arena she isn't going to assume that the local hissbeasts are the sort that can be safely ignored.

Of course, the fact that they're carrying something does make it a little hard to figure out where the sound is coming from - there are angles that are harder to check than others - but stopping is at least a good start for the time being.

"Can you see it?"