In dogs, humping (or mounting) can change in meaning as the animal ages:
As a dog matures, the behavior may persist due to hormonal changes , stress relief, or simple habit. Common Causes: matures humping
Some dogs use it as a self-soothing behavior to cope with high-stress situations. In dogs, humping (or mounting) can change in
Experts, such as those at Purina , suggest redirecting the dog's focus with toys or training if the behavior becomes excessive or inappropriate. Why Do Female Dogs Hump Things? - Purina such as those at Purina