The affection Thestrals show each other is a way of communication and interaction. Undoubtedly, deer care for each other, keeping watch while others feast.

The affection Thestrals show to human owners or friends when relaxed, their neck should be relaxed, not upright in an alert position and you will often see that the Thestrals are making soft noilses, a certain sign of relaxation. The body position will be relaxed, and Thestrals will step with low knees, wasting as little energy as possible as they move or feed.