If the quantities are too low for the nose to pick them up I think nature has converged on "too noisy to bother with".
Are the quantities too small though? Really foul-smelling small molecules can be sensed at least down to ppb concentrations. And the recent technical use of "eDNA" demonstrates there's signal to be had.
alt Hacker News
Are the quantities too small though? Really foul-smelling small molecules can be sensed at least down to ppb concentrations. And the recent technical use of "eDNA" demonstrates there's signal to be had.