One of the new budgies i got yesterday keeps chewing on his feet, i checked him and he is missing a toe on one foot but it looks like a old injury. There is no signs of mites or scaly face so what could be causing this behaviour?

If the feet are fine like you say then it might be a behavioral or anxiety thing. seeing he is new he might be rather stressed and this is how he reacts??

If they are in pain they can start chewing on their foots. :sad:

I have moved him to a bigger cage and he has stopped doing it.

I had a young budgie do that 2 years ago, He was 7 weeks old and I put him in the kindie cage and he was fine with all the others until I let him out onto my finger which I do quite often but this little fella wanted to get out all the time and sit on my finger. He would run up and the cage as soon as he saw me and when he didn't get out he started chewing off his toes (blood everywhere) I gave him probotic to carm his nerves. But it was an awful thing to watch.

But I believe it is a nervous thing, like an highly strung budgie with a manic disorder