Hackles

So was just wondering if someone could tell me the proper reason for a dog raising it's hackles? i always thought it was an aggressive thing, but then was sure that i read that it doesn't always mean this?

I noticed that Diesel's hackles are raised quite often sometimes when there isn't even another dog around? but she is just very excited and darting about outside on her own?? Can it just been i sign of excitement?

Moo raises her hackles a lot also, just something I assumed she did lol Xx

I've always thought it's to make the dog look bigger/feel bigger if they are the aggressor ??

its a sign of aggression and the dog is uncertain of a situation. Much the same as us when we see something frightening the hairs on our arms are raised. Its called piloerection and caused by adrenalin in the dog

It dates back to wild ancestors, as well. It makes them look bigger, but was also used for protection - their ancestors had very thick coats. When the hackles of those animals were raised, it would have made it very difficult for attackers to get a decent grip.

It's not necessarily aggression.
My girl raises her hackles several times a day yet my boy dosent.

Hackles can be aggression related BUT can be a sign if general alertness.

My girl is super sensitive to every lil noise etc, hackles up, she will investigate, then chill out once she's happy.
She is not aggressive at all.

Also used to keep warm!

I read that some dogs' hackled raise more than others, like some people blush easier than others. It's not necessarily aggression, just alertness or perhaps even interest. Loki's hackles raise when he seems very interested in something. Also agree with Eleanor about it being used to keep him warm. I let him out for the toilet and he comes back in with his hackles raised, presumably because he's absolutely freezing

Thanks all for the comments, good to know diesel isn't the only one that raises her hackles a lot, cause she's never shown any signs or aggression what so ever so was slightly confused by this but it must just be her alertness. Its not always a lot either maybe just 3/4 of an inch of the base of her tail an a wee tuft on her bum