If pecking is getting to the point where the birds are injuring each other, you might want to think about increasing the space allotted to the birds.
That being said, some chickens' beaks do get long, and need to be trimmed. I found our Dutch Bantams in particular needed their beaks trimmed regularly for some reason. But as Energyvet says, be VERY careful, as they do have veins and if you nick a quick in a beak, you're going to have blood a'gushin'!
I wrote an article on my website about beak trimming, which you can see here: http://www.pathfindersfarm.com/Beaktrim.html
Here are the steps:
Trimming a Chickens' Beak for Shows
It's not hard to trim your chickens beak, as long as you
take your time. This article will show you how.
What you'll need:
- A pair of dog or cat nail clippers.
- A nail file.
- Blood stop, cayenne pepper, or flour.
- A towel for your lap.
- A chair or stool to sit on.
Remove the chicken whose beak you wish to trim from its
pen. Sit on a chair or stool in a bright place with your
tools assembled near you. Put a towel over your lap to
keep yourself clean, and to wrap the bird in if needed.
Open your chicken's mouth gently, by pressing on the
sides of the mouth. Sometimes you must hold their heads,
as some birds don't like having their beaks clipped. With
male birds that have larger combs, you can hold onto the
comb with one hand and clip with the other.
Using the dog or cat clippers, gently clip a small amount
of the top half of the beak (the bottom half generally
doesn't need to be trimmed.) Doing this in small steps
works best, you don't want to go too far, as beaks have a
"quick" just like toes on a dog or cat. In some birds you
can see the quick, in those with darker beaks you cannot.
Clip the top half of the beak squarely, so that it is just
slightly longer than the bottom half. Then take your nail
file, and gently round the edges so that it follows the
natural shape of the beak. You can follow up with a slight
polish of baby oil if you'd like, but it's not required to do
If you cut too far and the beak starts to bleed, gather
some Styptic Powder, Blood Stop, cayenne pepper, or
flour in your fingers and place it against the bleeding end.
You will need to apply pressure here for several minutes,
you don't want to put a bleeding bird back in a pen with
other birds, who might attack it when they see blood
(chickens can be like that!)
Hope that helps!