'Best birthday ever!' Librarian learns of daughter's pregnancy with Dr Seuss book

This is the heartwarming moment a librarian learns she will become a grandmother on her birthday with a series of Dr Seuss-themed clues.

The woman, Colleen, is seen opening gifts on her birthday in a recorded Skype conversation with her daughter and son-in-law.

While the first gift is fairly innocuous, the second gift - The Cat in the Hat by Dr Seuss - raises some eyebrows.

Colleen rejoices as she learns she'll become a grandmother.

But then she opens her last gift - matching babygrows emblazoned with "Thing 1" and "Thing 2".

The clip was filmed in May 2013.