Their long tails are used almost constantly. Insects are abundant in rainforests. Tail movement reduces bites and disease risk. This keeps stress levels low. Tail use is rhythmic and efficient. It rarely stops.
This behavior prevents parasite overload. Comfort improves overall health.
It shows simple tools can be vital. A tail can be lifesaving.
Okapids may swat insects hundreds of times per hour.
Smithsonian National Zoo (si.edu)