Dogs inherited interest in sticks from wolf ancestors who used fallen branches to build dens for shelter and raising young.
Ancestral Interest
Chewing on sticks may relate to dogs retaining some of their wild ancestors' need to shred meat from bones for food.
Chew Urge
Sticks allow dogs to sniff intriguing nature scents from sap, fungus, leftover prey smells that appeal to their keen nose.
Scent Detection
Various wood tastes along with minerals from soil could explain dogs sampling sticks out of sensory curiosity.
Taste Test
Carrying branches taps into dogs' innate fetch drive and makes for a convenient take-along toy during walks.
Fetch Fun
After hunting or herding sessions, dogs were traditionally allowed to playfully gnaw sticks as a job well done reward.
Work Reward
Some experts theorize dogs just intuitively gravitate to wood out of ancestral memory we don't fully understand.
Natural Draw