Many young horses tend to try this as it is part of their communication. He could well be getting teeth too. I believe the best way to correct this habit is consistent training with the dually halter. As soon as he goes to nip school him. If he is running free with no halter and he goes to have a nip while you are with him then immediately send him away and only allow him back when he is submissive and docile. Once he has done join up a few times it will be easy to send him away as he understands what you are asking. Good luck - it is always a challenge but lots of fun starting off with a young one.

Hi Joanne,
Welcome to the forum!
Does your colt have company, some buddy to play around with?
Often the being intact will lead to solitude, no body contact with other horses.
If this is the case, please try to find a buddy for him, so he can do all natural things with another horse, and he'll be educated by the other one too.
Colts do bite more than most fillies, this is part of their path of finding their own hormonal identity. being only one year old, he cannot be a nuisance to mares yet, so he could even stay with some fillies for a while.
Since you have a Dually now, you can start his education with groundwork etc.,as MaggieF states above.
Important is that he's allowed to live as natural as possible among other horses.
Keep us posted,
Miriam

Hi, many thanks for your replies. I have had horses and ponies all my life, and when younger used to compete at quite a high level show jumping. I have been without a horse for about 8 years having concentrated on my career, and am just getting back into things now I have some spare time on my hands, so am a little rusty. We live on a small holding and at present he is on his own until I can find a companion for him, but there are other horses in an adjoining field to ours. I just have to fix the delapidated fencing in our other field which is now half done as of last weekend and then he definitely will have a little buddy to play with. He is the apple of my eye though, being a really well bred section D black colt with 4 white socks, he is a little stunner. I am doing groundwork with him and the dully halter is amazing.
Many thanks
Jo

He sounds really beautiful, Jo. All the best with him. I am sure he will just love a buddy to nip and play with. It will take the heat off you!! Great you are getting back into horses.

I know this is an older post but in case it helps someone... In Monty's book From My Hands to Yours he talks about nipping and his advice worked for me. I, too, had a yearling stud colt who was quite nippy. He had been fed by hand before I got him. Monty's method is to tap the front leg "shin" bone with the side of your boot when he nips. (Not kick him!) I went out to the pasture and intentionally rubbed on him and scratched on him and gave him the opportunity to nip, positioning myself so that I could administer the tap. After a few minutes he was less interested. A few more sessions of a few minutes like this and he has been "nip free" for months now!

Yep, that has worked for me too eshultz :)
On my late (deceased) horse when she was a 3year old and now on our current 3 year old. I actually didn't hear it from Monty, my old farrier told me.

I think that Monty gave us a great advice for nipping, but, what should I do if the horse is in stable (in his box)? How can I distract him (I can't get to his legs)

Is there any way you can work with him outside his box? Like tied up in the space ("corridor") between the boxes? The box is not the best place to work with an aggressive horse since they might get serious about defending their territory.
.
If you must keep it inside, try tying it up (two side ropes)facing the doorway. That way you can position yourself out of his reach and still be able to get to the legs.
.
You can also move him a couple of steps back and forth whenever he tries to bite - make him work when he is naughty. When he relax - you let go and resume brushing or whatever you did as if nothing has happened.
But you need to be quick (you have 3 seconds to act for him to connect 1 and 1) and consistent. Don't get angry, just firm, determined and calm.
This worked wonders with my horse.
Tapping his leg he took as an invite to play "bite the leg" instead and I got into trouble whenever my feet came too close to his.

Great suggestions :) thanks, I'll give a try :)

Tapping Tricka's front leg when she tried to bite just made her cross so that she would strike out. I found discipline with the dually each time her ears went back was much better with her - they are all so different. She is pretty good now.

It is all about teeth! And will be so the coming years! It is also NORMAL for horses to bit in to pressure - look at him with his friends in the pasture - they don´t do much then bite first at eachothers muzzle, then frontlegs and neck and hindlegs and oh you know:)
Boys are more up to this - it is a part of the genetics!
Look at hastpedagog channel and the starting the young horse - a sequence with 2 3 year olds and you see what I mean!
it is a delicate approach when just to ignore bad behavoir and school!
Good Luck!'
Warmest Ann Lindberg