When Sam accidentally gets fleas from Rocket, Jack must shrink down and find it somewhere on her head before squeamish Sam loses her mind.

Jack is a small alien who finds everything on Earth fascinating. Spurred on by his insatiable need to learn about creatures and phenomena from Earth and outer space, Jack boldly yet recklessly guides his alien friends through some tricky adventures. Developed for children from six to nine years old, Jack mixes humour, adventure, and science. The series helps children discover amazing new facts about the world and space around them.