In crowded net pens they can become epidemics.

The slave masters working in the crowded pens had instructions to identify and select any new sets among the captive populace on Earth.

First, producers who once relied too heavily on drugs to keep their animals healthy in crowded pens have changed their techniques in response to consumer concern about drug residues in meat.

By 11:02 he was headed for the crowded pens in other parts of the building where scores of prisoners spend much of each day waiting for their cases to be called and for vans to return them to Rikers Island.

As inmates spent two or more days in crowded holding pens on Rikers Island, waiting for beds to open up, extra chartered planes and buses were carrying prisoners to two new jails in upstate New York, the only available space in the system.

They were kept away, thwarted by police barricades that created crowded pens on Second and Third Avenues.

Much remains unknown about how the virus spreads, although it is known to move in the water and from fish to fish in crowded pens.

The medical wards were as crowded and miserable as the slave pens the robot Erasmus had once kept on Earth.

A few years ago, I visited a free-range chicken farm in Upstate New York and was surprised to see that the $10 apiece birds were enclosed in crowded pens, though outdoors.

Additional watcheyes converged above the crowded pens where the feeding humans jostled each other.