;Temperature
:When the foraging organism's optimal foraging temperature is present, the organism will be more likely to search for food. Often, the further temperature falls out of this range, the less likely foraging will occur, thus, the less likely trail pheromones will be deposited.
;Season
:Alongside with temperature, foraging occurs more during some seasons than others. With a change in season comes additional factors: a change in predators organism to avoid, change in food supply, and change in light availability. Often foraging organisms choose preference over such factors.
;Humidity
:If it is too humid or not humid enough, organisms may choose not to forage.
;Other chemicals
:Other surrounding chemicals may interfere with strength of pheromones.