Chemotaxis: movement towards desirable chemicals, and away from unpleasant ones.

Pleasant dreams are, of course, more attractive than unpleasant ones, but after all, we do not live in a dream.

She consistently finds that sounds pleasant to the ear also taste good, and unpleasant ones don't.

I did the bidding of the Prince in all ways, including the unpleasant ones.

There are no inspiring surprises, but at least no unpleasant ones, either.

The memories described are unpleasant ones, of conflict with family, authority and peers.

That's what most of us do when we're talking about very private matters, especially unpleasant ones.

Many new crossword players come to the little white and black squares because of lifestyle changes, often unpleasant ones.

Examples shall therefore be made of you-but not unpleasant ones, for you.

The memories they hold on to can be unpleasant ones.