Mammals and oviparous animals have certain differences, mainly in their breeding methods, respiratory methods, and characteristics. These differences can clearly distinguish mammals from oviparous animals, and the methods for doing so are quite simple.

1. Different breeding methods:

Oviparous animals reproduce through the hatching of eggs, such as frogs and chickens. They are responsible for raising their offspring outside their bodies, relying solely on the yolk within the eggs as a source of nutrients; whereas mammals reproduce through viviparity, nurturing their offspring within their bodies, surviving on the nutrients provided by the mother.

2. Different respiratory methods:

Mammals breathe using their lungs, such as dolphins, whereas oviparous animals breathe using gills, for example, freshwater fish.

3. Different characteristics:

Mammals are covered with fur and are endothermic animals, such as dolphins, which do not require hibernation. On the other hand, oviparous animals are ectothermic, such as snakes, which need to hibernate during winter.

Mammals have a relatively prosperous brain compared to humans, which allows them to exhibit more complex individual behaviors than other small animals. However, it is worth noting that the platypus is a mammal, but it is oviparous, therefore, it is considered a lesser mammal.