I WONDER - Do All Mammals Have Hair? Me Pregunto - Todos Los Mamíferos Tienen Pelo?

The video explains that most mammals give birth to live young and provide parental care, such as feeding milk. It highlights the kangaroo as an example of extended parental care. However, there are exceptions like the platypus and spiny anteater, which lay eggs instead of giving birth to live young.

What is the significance of the kangaroo's method of caring for its young?

Which two species of mammals do not give birth to live young?