Invisible

The red-furred creatures bumbled unseeing past Smythe and Rennett.  They weren't exactly mammals, but the survey team called them monkeys anyway.

Smythe scratched under his bonnet and sighed.

"Hss!" Rennett warned.  The monkeys, catching momentary sight of the disturbance, paused and murmured uneasily.  "Don't adjust the suit, dammit.  You've been told often enough."

"Why did it have to be pink that they can't see?" Smythe whined.  "I feel like an idiot."

"Try thinking instead about all the frequencies we can't see, and what might take advantage of that to watch us."

Smythe was quiet for the rest of their shift.