Their unnatural behavior was ominous without implying aggression.

Daniel remembered the surly unnatural behaviour of Gomo and the other driver when he had met them on the road.

Experience had taught him that such unnatural behaviour variably announced the arrival of the gentleman with the thistle-down hair.

They said it was barbarism to teach our animal cousins unnatural behavior, or to have them in captivity at all.

Being naturally alert, he spied out the barman's unnatural behaviour almost at once.

What would have seemed completely unnatural behaviour had now become almost second nature to her.

But the cats were far too mannerly; their unnatural behavior increased his unease.

This data may represent unnatural behaviour or states of mind, and must be considered carefully during interpretation.

But you know that the deeper causes of this unnatural behavior were removed long ago, and now we treat each other as equals.

We do not indulge in unnatural behavior.