Stevenyc.....I take you point, but a kangaroo is a bit different from a mouse.
The kangaroo carries it's young in a pouch until they are quite large. It's amusing to see two huge feet sticking out of the pouch whilst the youngster has a nap.
But amazingly, the kangaroo not only has a baby in it's pouch but a fertilised egg hidden away for safekeeping. If the kangaroo is in danger (bushfire, dingos, hunters, etc) it will ditch it's youngster and escape to safety. Then it will place the fertilised egg in position to breed again.
The big Red kangaroo towers over a man and is very dangerous. It will lean back on it's tail and gut a man or dog so easily with it's big toes. They have a harem of does and it is not wise to approach them. Interestingly menstruating women are at high risk of attack.
I hand-raised a kangaroo from when it was a little fur-less joey. Had to feed it every 4 hours for 3 months. Never had any sleep. It would love playing games with our cattle dog. The blighter would be covered in mud then lope into the house looking for food leaving a red mud stain trail from his tail all through the house.
Ah...I miss Rhubarb. An ignorant neighbour's electric fence finally got her.
It never occured to me that her forebears 6,000 years ago could have been mice.