They breed best in tanks without other species.

For about a year, wildlife biologists have been trying to breed them in captivity, without success.

I think they'll be astonished at the runty crops their fields will produce next season, after they have to breed them without my advice.

The vegetarians in their already huge numbers began to breed almost without danger.

What they are doing here, essentially, is breeding without check.

Because only one worm may reach such an Eden, it helps to breed without a partner's help.

If they breed without control, the whole wheel will fill up.

This will give all marine life in the area a chance to breed and live without disturbance.

The color is important, because flamingos do not seem to breed successfully without it.

They breed two or three times a year, probably without any distinct breeding season.