New backyard chicken farmers, listen up. Here are a few common mistakes to avoid:

• Buying a coop that’s too small. Leave enough space to expand your flock.

• Failing to consider the dog. Whether it’s the family dog or a neighbor’s dog running loose, just one playful bite that breaks the chicken’s skin and the dog will develop a taste for blood. About half the “replacement chickens” sold by Steven Bibula of Orchard Ridge Farm in Gorham are for chickens killed by a dog.

• Expecting longevity in chickens and becoming too attached. To avoid disappointing their children, adults buying replacement chickens often want a chicken that looks like the one that died, Bibula said. “But if you go into this looking at it as a learning opportunity, a maturing opportunity for the child, this is a great opportunity to say ‘Look, this is a part of the life cycle. If we choose to have birds, you’re going to outlive them,’ ” Bibula said.

• Expecting the chickens will be compatible with your landscaping. Chickens do not respect low fences, which can lead to angry neighbors.

• Skimping on the coop. Most pre-fab chicken coops are poorly constructed and lack adequate ventilation, said Kathy Shea Mormino, a backyard chicken farmer in Connecticut with a large internet following. Chickens need adequate ventilation in summer, and a dry, draft-free coop in winter. n Failing to predator-proof the chicken coop. Raccoons and hawks can reach right through chicken wire. Defend the coop with hardware cloth secured with screws and washers, not staples.