A type of body language that occurs when the hair over the spinal region of the back bristles and stands on end. It can express different emotions depending on context, but it is commonly associated with aggression.
reference: Martha Knowles 2023, ‘Raised Hackles’ or Piloerection – Dog Body Language, <https://www.silentconversations.com/raised-hackles-piloerection-dog-body-language-silent-conversations/>
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