BOSTON (CBS) — Seven baby African penguins in Boston had a weigh-in Wednesday.

The little chicks — ranging in age from six-weeks-old to just two-days-old — are at the New England Aquarium.

They are too small to be part of the exhibit now, but once they’ve grown more and learned how to swim, the chicks will join the over 90 other penguins of different species living at the aquarium.

Baby African penguins at the New England Aquarium (WBZ-TV)

This is the New England Aquarium’s second round of penguin chicks that has hatched this year. The penguins are weighed every other day to track their progress.

A baby African penguin is weighed at the New England Aquarium (WBZ-TV)

According to the aquarium, penguins grow 30 times their birth weight in less than two months. An adult African penguin typically weighs between six and a half to eight pounds.