Scienter Action means “Action when there is Knowledge”. This is the principle applied in respect of animals.

Animals are broadly classified in to two categories.

1. Ferrae naturae and

2. Mensuetae naturae.

Ferrae Naturae means ferocious animals which are by nature Ferocious. The law relating to this, under the extended meaning of Ryland V. Fletcher, is that the very bringing and keeping of such animals is prohibited.

Mensuetae naturae means domestic animals which are by nature docile and obedient. But, they may have a tendency to become ferocious under some circumstances. The owner may or may not know the dangerous propensity of the animals. If he does not know the propensity, he is not liable in tort. However if it is possible to establish that the defendant had the knowledge of the dangerous propensity of the animal, the defendant becomes liable under “Scienter Action”.

In respect of ferocious animals like Lion, Tiger Chimpanzee etc., the very bringing is prohibited because the experience of human beings shows that these animals like Dogs, Cats, Cows, Bullocks, Donkeys, Horses, etc. are not by themselves dangerous to human society. But the domestic animals may develop a propensity to cause harm or injury and the owner is liable if he has the knowledge of this propensity. In a number of cases decided, the Courts have held that in order to constitute a tortious liability it must be established:

(1) That the animal was savagery

(2) That the defendant knew or had knowledge of the tendency of his animal.

In Hudson V. Roberts : The bull of Roberts gored Hudson on seeing in his hands a red handkerchief. Held defendant liable as (1) the animal had so attacked others many times previously (2) that defendant had knowledge of it.

In Jackson V. Smithson : The facts were that one person by name Catherine was attacked by a ram, which goaded her and threw her down. Held, defendant liable as he had knowledge of the propensity of the animal.