Let’s start at the beginning with chicks in the brooder. Chicks don’t just peck each other for lack of something to do. There is an underlying problem causing them stress and/or aggravation. As any living creature, the first and foremost necessity for well being is comfort.
Providing chick starter crumbles and fresh water is a given, so we can certainly rule out hunger as the stress factor. It is my opinion there are two other very important factors to consider. Living environment and lighting, with significant emphasis on the latter. Overcrowding may or may not be the culprit in their acquired pecking behavior. However, if ample space is not provided away from a heat source, comfort is indeed compromised.
Always provide more than one feeder so weaker birds are not bullied. It only takes one drop of blood for the pecking disaster to begin, remember chickens are in fact cannibals. Also, by week 3, keep them busy with offerings of green grass, especially when you witness aggression.
Now let’s get to the nitty gritty of the pecking problem. Lighting, lighting, lighting! A brooder lamp is necessary for warmth but it shouldn’t be a blast of blinding light. Especially if you have the chicks in a small brooder and there’s no way to escape the annoyance.
I’m not at all a fan of the clear white bulbs and switched a long time ago to RED. They provide a calming environment, and as a bonus any minor pecking that’s caused an injury is better disguised under a red lamp.
You may want to make the switch from heat lamps altogether and switch to radiant heat from a Brinsea brooder. This will solve your fluctuating temperature problem, and providing you have a good number of chicks, it will be sufficient in keeping them warm.
Note: If it’s brutal cold… you can supplement with a low wattage red heat lamp. Low wattage heat bulbs are sold for reptiles, I usually use a 50 or 100 watt, depending on how cold it is.
For injuries, no matter how slight, I use a product called Blu-Kote. It has healing agents and the purple dye in the treatment hides the battle wounds. You’ll find this product at your local feed store.
I’m convinced that happy and content chickens start in the brooder. It’s easy to tell if the brooder has comfort zones. You should see some birds huddled together under the heat source, some resting alone, some scratching in the litter, and some eating. Watch your chicks, their behavior says it all!