The correct answer is option 3, bacteria. Bacteria are single-celled organisms that do not have complex physiological systems like animals. They do not have specialized glands or organs that produce hormones. Hormones are chemical messengers that are produced by glands in animals, including humans, and are responsible for regulating various bodily functions.

On the other hand, rats, monkeys, and cats are all animals that have well-developed physiological systems and produce hormones. Hormones play a crucial role in the growth, development, and functioning of these animals. Therefore, it is expected to find hormones in these animals.

However, it`s worth mentioning that certain bacteria, called endocrine-disrupting bacteria, can produce compounds that can mimic or interfere with the actions of hormones in animals. But these compounds are not considered true hormones and do not regulate bodily functions like hormones do.