I have pony that I have been doing clicker traing with and he responds very nicley to it but every time he sees my hand or arm near his head he bites me looking for food.He is very mouthy to begin with and I was wondering if I should change the way I do it or maybe try another method, any suggestions.
This is a normal response for a horse. They look for food with their mouths, and they go straight in for it with their heads. That is what they do.
What you haven't done is make it clear to him foundation for the clicker training. Clicker training can be a very useful tool, but unfortunately like many forms of training people just go pick it up and use it often with little knowledge of the fine detail that is important to be safe and effective.
If you do not set the foundation correctly then one of two things happens.
The first is what you are seeing - the constant search for treats. This is because he has not been taught the clear enough distinction of the process - cue, try, click, reward.
The second and for me worst outcome is when I see horses that become obsessed and are constantly offering repetitive behaviours like a nervous twitch, looking for the treat.
So what you should be doing. Firstly NEVER carry treats in your pockets. I always recommend people either have a little pouch, or easier still a bum bag (or fannypack as it is in the US). You only do clicker training when you are wearing this. Therefore the horse knows when you try for behaviours and when to relax.
Secondly use the clicker training to reward standing and not looking for food. When he looks for food give him a cue like 'leave'. The moment he moves his head away click and reward.