Things that could die, and things they could walk on... Those were trails worth pursuing. Taura did Rita a favor by listing some of the more metaphorical interpretations, as well as some items she may not have thought of right away. Machines could be considered 'dead' when they no longer functioned... but there weren't many that could be walked on, and most were far noisier while functioning.

Now which of those things made noise when walked on...?

Goku's rambling was becoming distracting again, though, and Rita had to stop to mutter, "Idiot," at him before returning to her thoughts. But those had already been disrupted by the brat's inane prattling. In her mind, she was picturing a 'crunchy noise', sort of like what she'd hear walking in the woods in the fall...

... Wait. Could that be...?

"What about leaves?" Rita asked suddenly. "They crunch under your feet once they've dried up, but fresh ones don't make any noise."