You’ve heard the expression, “Don’t get your hackles up!” And you’ve probably seen your dog’s hackles – the fur along their shoulders and spine – stand on end.  Known as piloerection, this automatic response is similar to goosebumps in humans.

While we often are told that raised hackles are a sign of aggression, they actually just indicate a state of heightened arousal. When fur is piloerected, it may mean that a dog is feeling afraid or defensive (and may or may not become aggressive), but it also could indicate uncertainty, curiosity, or surprise!

For an interesting read on piloerection, check out this blog post.