Most own midsize stocks - and some mighty aggressive ones at that.

Some species, usually the larger, more aggressive ones, are only to be found in very small numbers.

It had become clear to me that defensive tactics must be adopted as well as aggressive ones.

You see, the transmitters are the large, strong, aggressive ones.

"The aggressive ones would pounce on the crab," Anderson told me.

Quieter children were more likely to be left alone than aggressive ones, according to the study.

Hugh's gone to get bigger more aggressive ones from ant nest next door.

Even the more aggressive ones will go away eventually.

"There is such competition between travel destinations, and the most aggressive ones are trying to get a leg up," he said.

Passive males tend to have greater success in courting females than aggressive ones.