Tom Silva's chickens pump out 1.4 million eggs a day, but his operation looks more like a prison than a farm.
To reach his hen houses, an intruder would have to scale 8-foot (2 1/2-meter) fences topped by razor wire, then sneak past surveillance cameras.
"Biosecurity" is the buzzword du jour at chicken, turkey and egg operations across the United States. A bird flu pandemic sweeping through flocks in Southeast Asia and beyond has spurred American commercial farmers to tighten their defenses.
"This is certainly the biggest issue facing the industry today, no question about that," said Richard Lobb, spokesman for the National Chicken Council.
The stakes are especially high in California, where a $2.5 billion ( 2 billion) poultry industry ranks among the top 10 producers nationwide for chicken, turkey and egg output. State officials say migratory bird routes that stretch southward from the Bering Strait and down the West Coast could bring the disease by this summer.