Infant wallaby takes first peeks at Washington earlier this month, after months of being carried in mother’s pouch after birth. (Smithsonian’s National Zoo)

The Washington Nationals have limited the types of bags that can be brought this season to Nationals Park, and fans looking for ways to carry their stuff might envy an animal at the National Zoo, who carries its newborn in a built- in pouch.

The newborn , known as a joey, is a wallaby and has been carried about since birth in the pouch that forms part of the anatomy of the mother wallaby, named Victoria.

According to the zoo, the joey poked its head out of the pouch on March 11.

Keepers were not surprised, the zoo said last week.

After all, the infant was born several months ago. Exactly when, the zoo said, is not so clear.

At birth, wallaby pups weigh less than an ounce. Although underdeveloped in many ways, they can use their tiny arms to climb into their mother’s welcoming pouch.

Infant wallaby takes first peeks from mother’s pouch at the National Zoo earlier this month. (Roshan Patel/Smithsonian’s National Zoo)

There they stay, for weeks, nursing and completing their development.

In a month or two, the zoo said, the joey will begin excursions outside the pouch, spending time both inside and out.

After about nine months, the zoo said, they spend all their time outside. The joey and its parents, Victoria and Sydney, are Bennett’s wallabies.

They are related to the better-known kangaroo but are different.

The zoo said the last time a Bennett’s wallaby was born there was 1989.