Little Orphan Happy/Body Rockers

S1 E4: It's Mother's Day, but Happy can't bring himself to celebrate with the Higgenbottoms because he doesn't know where his own mom is. Bessie conducts a thorough search to find Happy's long-lost mother, but all in vain. Just when they’ve given up hope, a dog shows up at the door – it's Happy's mom! But it soon becomes clear that she isn't exactly the most courteous houseguest, and she isn’t even all that nice to Happy, her own son. At the San Francisco Science Exploratorium, the Honeybees are going through some interactive exhibits about human anatomy. Penny and Bessie are separated from the group and find themselves in a science experiment where they've been shrunken down and zapped into a human body! Or that's what they believe.  What really happened is that they have stumbled inside a giant exhibit of the human body.