- SpongeBob SquarePants
- Patrick Star
- Squidward Tentacles
- Margie Star (mentioned)
- Sandy Cheeks
- Incidental 41
- Fleas (debut)
- Cross-Eyed Armadillo (mentioned)
- Incidental 14
- Incidental 15
- Incidental 17
- Incidental 82
- Incidental 48
- Incidental 23
- Incidental 10
- Incidental 107
- Incidental 27
- Incidental 46
- Incidental 49
- Incidental 6
- Incidental 92
- Incidental 155
- Incidental 108
- Orange lady
- Incidental 21
- Incidental 63
- Incidental 105 (orange; normal)
- Incidental 64
- Incidental 106
- Incidental 106 (blue)
- Incidental 37A
- Incidental 45
- Incidental 73
- Incidental 2
- Incidental 158
- Incidental 104
- Incidental 67
- Incidental 37B
- Incidental 13
- Incidental 7
- Incidental 60
- Old Man Walker
- Incidental 153
- Incidental 152
- Incidental 151
In the beginning of the episode, SpongeBob and Patrick are crying, because Sandy has gone to Texas for two whole days. They decide to take the time until she comes home to prepare for and throw her a welcome home party. During their party, SpongeBob and Patrick notice that Sandy is scratching and biting her fur. Sandy explains that upon her return from a science convention in Texas, she unknowingly brought back a flea. Sandy asks SpongeBob to open her briefcase and take out the flea collar.
The flea jumps out of her fur and lands on SpongeBob. SpongeBob gets bitten and grabs the collar. The flea then lands on Patrick and bites him, causing Patrick to take the collar. They then fight over the collar, which causes Sandy to grab the collar and wrap it around all three of them. The flea then reproduces, causing the flea collar to be eaten away, rending it useless. Fleas take over Sandy's tree dome, and no one can escape the dome. Patrick blames Sandy for bringing the flea and getting infected, then SpongeBob blames for throwing the party, which causes SpongeBob and Patrick to fight. Sandy breaks up the fight and tells them that arguing is not going to help save themselves as long as they work together.
Patrick comes up with the idea of creating a tower to the tree, only to climb up and get an apple. Sandy is annoyed at Patrick's stupidity and the group takes refuge in the tree. But it proves to be useless as the fleas continue to spread all over the treedome.
SpongeBob states they may be living in a sea of fleas instead of salt water, thus giving Sandy an idea on how to get rid of the fleas. Sandy then crashes into the cauldron with fleas by infecting all their space in the dome with saltwater. This drowns and gets rid of the fleas, but all the Bikini Bottom citizens are stuck in the dome at the end. SpongeBob tells Sandy its good to have her back, as the episode ends.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
• Tentically Speaking - Sage Guyton, Jeremy Wakefield [Title card]
• Blue Tide - Sage Guyton, Jeremy Wakefield [SpongeBob crying]
• Steel Licks 1 - Jeremy Wakefield [Squidward gardening]
‣ Main Street - Alec Gould [SpongeBob and Patrick preparing for Sandy's arrival]
• Hello Sandy Song - Nicolas Carr ["Welcome home Sandy, you know that we missed ya..."]
• Wahini Wobble - Nicolas Carr, Sage Guyton, Jeremy Wakefield [Sandy scratching herself]
• Question Sting - Nicolas Carr ["You ready?"]
‣ Drama Link (B) - Hubert Clifford [flea biting Sandy]
• Tentically Speaking - Sage Guyton, Jeremy Wakefield [Sandy explains what a flea is]
‣ Bach's Toccata - Peter Lea-Cox ["I'm gonna turn into a vampire!"]
‣ Six Powerful Cues (D) - Wilfred William Burns [Patrick takes the flea collar]
• Grass Skirt Chase - Sage Guyton, Jeremy Wakefield [they fight over the collar]
‣ The Creature (a) - Gregor F. Narholz [Flea lays eggs and two fleas emerge from them/Three fleas jump off of SpongeBob, Patrick and Sandy/Fleas multiplying]
‣ House of Horror - Larry Hochman [fleas biting SpongeBob, Patrick and Sandy]
• Squiddy G - Nicolas Carr, Barry Anthony [plays on Squidward's headphones]
• Sponge Monger - Sage Guyton, Jeremy Wakefield [Sandy stepping on fleas]
‣ Drama Link (D) - Hubert Clifford [SpongeBob screams]
‣ Big Bad Giant - Paddy Kingsland ["Okay, you know what?"]
• Nude Sting - Nicolas Carr ["I do not play games."]
‣ They're Coming! - Trevor Duncan [they hide in the treehouse]
• Harp! - Nicolas Carr [Sandy gets an idea]
‣ West Side Rumble - Sam Spence [fleas washed away]
• Tentically Speaking - Sage Guyton, Jeremy Wakefield [ending]
- This episode is available on the To Love a Patty, SpongeBob's Pest of the West (UK version), Season 5 Volume 2, Sportingly Sandy, SpongeBob StarPants, The SpongeBob SquarePants 8 Season DVD Collection, The SpongeBob SquarePants Collection, Kids Double Pack: Volume 6, The Ultimate SpongeBob Box Set, SpongeBob's Legendary Adventures, Really Big Box Set, First 100 Episodes, Holidays with SpongeBob 3-DVD Gift Set, SpongeBob SquarePants Vol. 7, Complete Fifth Season, Beware the Hooks, From the Beginning, Pt.2, and The Best 200 Episodes Ever DVDs.
- It is also a bonus feature on the Back at the Barnyard: Club Otis DVD in the UK.
- Currently retired critic Mina Rhodes of the DVD Verdict called this episode in a review of To Love a Patty, one of the better ones included in the disc, praising in particular the fleas themselves for being "highly memorable—mostly because they're downright frightening looking," and the episode in general for "regaining some of the series' former wit," despite calling the episode derivative of the episode "Wormy."
- The scene where SpongeBob and Patrick cry tears onto each other is similar to a scene from The SpongeBob SquarePants Movie.
- When Patrick regurgitates Sandy's cake, it is in the shape of Texas.
- The bus driver who hates SpongeBob's singing is Peterson Nat Tucker.
- When Squidward does a power walk, he says, "Heel, toe, heel, toe" just like in "Bucket Sweet Bucket."
- When Squidward is power walking, the song he is listening to sounds similar to the smooth jazz song from "The Thing."
- It can also be heard in "Bucket Sweet Bucket" and "Enchanted Tiki Dreams."
- When Sandy opens the door, the water in the ocean is all filled up, similar to "Reef Blower."
- In this episode, SpongeBob does not know what fleas are, but in "Squirrel Jokes," he makes fun of how squirrels have many fleas.
- This is the first time that "Tentically Speaking" plays.
- This is the second episode Sandy is seen without her helmet and wearing her suit inside her treedome. The first episode this happened was in "Chimps Ahoy."
- The badly-played fanfare heard in this episode when SpongeBob says "Patrick, to the Treedome!" (also heard in "Mermaid Man vs. SpongeBob" and "Appointment TV") was performed by Stephen Hillenburg himself, according to a tweet from sound designer Jeffrey Hutchins.
- The title references the name of the play "A Flea in Her Ear."
- The monster face the fleas make looks similar to Bowser's face from the Super Mario Bros. games.
- When SpongeBob says, "Glad to have you back, Sandy," the outline to Sandy's helmet almost disappears.
- Before Patrick eats the cake, it is circular, but after he does, it is shaped like Texas.
- When Patrick talks about being bit by "vampire flea," after he falls on the ground, his flea bites are gone.
- When Sandy says "There is no such thing as vampires," the flea collar that SpongeBob was wearing is gone, and it comes back when Patrick is about to take it from SpongeBob.
- When the flea hatches two eggs, more than three jumps out.
- When one of the fleas lands on SpongeBob, the top of his tie turns white for a moment.
- The collar keeps changing size when different people wear them.
- The fleas could not destroy the flea collar; it would kill them when they touch it.
- Patrick cannot possibly eat the apple from Sandy's tree since he is wearing a water helmet.
- Patrick eats an apple from Sandy's tree, while the tree is obviously an oak tree. In a later scene, Sandy even picks an acorn to throw at the fleas.
- It would be impossible for Sandy's treedome to empty the entire sea, with or without the mass of the Bikini Bottomites.
- In reality, the treedome would just break apart if it tried to fit all of the ocean water inside of it.
- There should not have been any contrast between when there was water in the treedome and when there wasn't because the show is not contrasted this way when the underwater setting is shown.
- When Sandy moves her arm to look at the flea, bubbles appear, despite there being no water in the treedome.
- At the end of the episode Patrick, SpongeBob, and Sandy have a glow on the outline of their bodies.
- In the Welsh dub, Luke Brookshier, Tom King, and Steven Banks are all listed as writers of this episode, even though none of them wrote this episode. Brookshier and King are also erroneously listed as storyboard directors.