The semantic field of a word is very large and many animal nouns are applied to human beings. Therefore, it is not always clear what animal nouns refer to although most people think of the animal itself. To those people, a cat would be a small animal that catches and kills mice and birds while other individuals might think that it refers to a human being since a human’s behaviour can remind them of a cat’s characteristics. The aim of this study is to show how nouns that refer to animals are used to describe human beings. I also investigate whether some of the nouns are more frequently used to describe women or men and if they are applied to women and men with special characteristics. Four animal nouns are chosen, cat, dog, pig and rat in the singular as well as in the plural, and the data is retrieved from The Guardian / The Observer 1999 and 2000. The main aim of this corpus study is to investigate how the lexical items cat, dog, pig and rat are applied to people in contemporary English. The results of this investigation show that the majority of the animal expressions applied to people illustrate the dictionary definition but there are also some deviations and examples that cannot be found in the dictionaries consulted. In some of the diverging examples the original meaning has changed and they can be interpreted in more than one way. The results of this investigation also show that the highest number of animal expressions is applied to people in general, the lowest number is applied to women and the number applied to men is more than twice as many as those applied to women.