Kangaroos usually have 1 youngster each year.
1 month
At about 1 month old, the tiny embryonic kangaroo emerges from its mother's body and slowly climbs up her fur around the abdomen, and into her pouch.
Once inside the pouch, the newborn latches onto a teat (nipple) which swells inside its mouth.
As newborn marsupials do not have the ability to suck, muscular action from the teat squirts milk into the baby's mouth.
Newborns are about the size of a Lima bean!
9 months
A then spends baby kangaroo spends up to 9 months living and growing inside its mother's pouch.
After that period they can become active outside the pouch, returning only to feed.
When that happens, another baby joey can be born.
At this stage 2 types of milk are be produced, one for the active joey, and one for the still developing joey inside the pouch.
That's a bit like producing full fat and semi skimmed milk at the same time!
18 months
The joey remains near the saftey and food until it is around 12 to 18 months of age.
Kangaroos can have 3 babies at one time
One becoming mature and just out of the pouch, another developing in the pouch and one embryo in pause mode.
There are 4 teats in the pouch and, as already mentionned, each provides different milk for the different stages of development.