Many animals signal one another by secreting powerful chemicals called pheromones, usually from special glands, or by means of their urine or feces.
Daudzi dzīvnieki raida cits citam smaržas signālus ar feromoniem, ķīmiskām vielām, ko parasti izdala īpaši dziedzeri vai arī satur urīns un izkārnījumi.