Viviparous as they give birth to young ones
like hen.human..it happens

Explanation:

Animals that give birth to live young are called viviparous. This means that the offspring develop inside the mother's body and are born alive.

Viviparity is a reproductive strategy found in various groups of animals, including mammals, some reptiles, and a few species of fish and invertebrates. It allows for internal fertilization and provides the offspring with a protected environment to develop until they are ready to survive on their own.

Advantages of Viviparity:
- Increased survival rate: By developing inside the mother's body, the offspring are protected from predators and environmental hazards.
- Nutritional support: The mother can provide nutrients and oxygen directly to the developing offspring through structures like the placenta, ensuring their proper growth and development.
- Parental care: Viviparous animals often exhibit parental care, which can include behaviors such as nursing, grooming, and protection. This further enhances the survival chances of the offspring.

Examples of Viviparous Animals:
1. Mammals: Humans, dogs, cats, elephants, whales, etc.
2. Reptiles: Some species of snakes, such as boas and pythons.
3. Fish: Some species of sharks, such as the great white shark and hammerhead shark.
4. Invertebrates: Some species of insects, such as aphids and certain species of butterflies.

Comparison with Other Reproductive Strategies:
- Oviparity: Animals that lay eggs and have external fertilization are called oviparous. Examples include birds, reptiles, amphibians, and most fish.
- Ovoviviparity: Animals that retain the eggs inside their bodies until they hatch are called ovoviviparous. The eggs develop and hatch internally, but there is no placental connection or direct nutrient exchange between the mother and offspring. Examples include some species of sharks and reptiles.

In conclusion, animals that give birth to live young are called viviparous. This reproductive strategy provides numerous advantages for the survival and development of the offspring, and it is found in various groups of animals.