[[quoteright:250:http://static.tvtropes.org/pmwiki/pub/images/250px_bart_the_mother.png]]
Bart's troublemaking claims the life of a bird, and in repentance, he decides to take care of the eggs in its nest -- until he learns that the abandoned baby birds are actually reptilian pests who feed off birds.

This is the last episode written by David X. Cohen before he left to work on ''WesternAnimation/{{Futurama}}''. This is also the last appearance of Troy [=McClure=]. The episode is dedicated in the memory of Creator/PhilHartman who voiced [=McClure=], Lionel Hutz, Lyle Lanley, and various other characters on the show. Hartman was tragically killed by his wife 4 months before the episode aired.

!! Tropes:
* AccidentalAimingSkills
-->'''Nelson:''' You even compensated for the crooked sight!
* TheAtoner:
** Bart, after Marge punishes him by neglecting him and Bart realizes that he made orphans out of the eggs in the nest, decides to take care of them in repentance.
** Just in case you thought Marge was a little too hard on Bart for pretty much disowning him earlier (and also making it hard for him for take care of the eggs by barging into his treehouse and unplugging the cord connected to the incubator), she helps him warm the eggs and even allows him and the lizards to escape from getting killed.
* BreadEggsMilkSquick: When the eggs finally hatch.
-->'''Marge:''' I see a foot!
-->'''Lisa:''' I see an eye!
-->'''Bart:''' I see a neck!
-->'''Homer:''' [[WhamLine I see a horn!]]
-->'''Lisa:''' (''confused'') A horn?
-->(''the eggs hatch, revealing lizards'')
* ChewOutFakeOut: After Bart reveals that he began taking care of the dead bird's eggs, Marge looks a bit disapproving at first... but then [[SoProudOfYou she smiles and gives Bart a hug]].
* CruelMercy: A non-lethal variant. When Marge finds out Bart has killed the bird, he realizes he can't run from this and says he deserves to be punished. Then Marge ignores him and lets him continue to "kill things", even though Bart clearly isn't proud of what he did either.
* DisappointedInYou: Marge, after Bart kills the bird, and just ignores him. She forgives him after discovering the birds' eggs.
* EndOfAnAge: This was the last Simpsons episode to use the production code "#F##", the last Simpsons episode to feature Creator/PhilHartman (playing Troy [=McClure=]), and also the last full-length Simpsons episode written by David S. Cohen[[note]]his last Simpsons work was the "Treehouse of Horror IX" story "Starship Poopers"[[/note]], who became executive producer and head writer for ''WesternAnimation/{{Futurama}}'', adopting the name "David X. Cohen" there.
* GettingCrapPastTheRadar: The episode has some fun using very naughty-sounding words on account of them all pertaining to species of bird.
-->'''Skinner''': It's already wiped out the dodo, the cuckoo, and the nene. And it has nasty plans for the booby, the titmouse, the woodcock, and the titpecker.
* HypocriticalHumor: When Lisa and Maggie cheat at skeeball to get tickets, Nelson calls them out for this and then steals tickets from a machine that dispenses them.
* IDidntMeanToKillHim: Bart tried to explain to Marge that killing the bird was an accident. She doesn't buy it.
* IHaveNoSon: Marge realizing that her constant punishments of Bart never sink in and coming to the conclusion that he can do whatever he wants has this sort of effect.
* JerkassBall: Nelson. While this is usually par the course for him, this episode depicts him at his absolute worst since "[[Recap/TheSimpsonsS1E5BartTheGeneral Bart the General]]." His treatment of Milhouse at the Family Fun Center and his bullying taunts to Bart are more mean-spirited than usual, and he tops it all off by insisting that Bart shoot a bird and expressing absolute glee when its killed. No wonder Marge wanted Bart to stay away from him.
* JerkassHasAPoint: As harsh it may have been, Marge did have every reason to be angry and fed up given Bart is normally an endless troublemaker and she insisted he shouldn't hang out with Nelson (for good reason).
* KarmaHoudini: Lisa, Maggie and Nelson don't suffer any consequences for the cheating and the stealing they did to get tickets.
* MamaBear: By the climax both Bart and Marge feel this way towards Bart's lizards. Bart because he raised them, and Marge because she knows how it feels to love a kid even when everyone else thinks they're a monster.
* AMillionIsAStatistic: PlayedForLaughs towards the end.
-->'''Lisa:''' I don't get it, Bart. You got all upset when you killed one bird, but now you've killed tens of thousands, and it doesn't bother you at all.
-->'''Bart:''' Hey, you're right ... [[IgnoredEpiphany I call the front seat!]]
-->'''Lisa:''' You had it on the way over!
* MythologyGag: When she learns Bart has disobeyed her by hanging out with Nelson, Marge says "Bart is in deep, deep trouble.", referring to the Simpsons song "Deep, Deep Trouble".
* NiceJobFixingItVillain: In as much as you could call Skinner a [[VillainyFreeVillain villain in this case]], but his attempts to forcefully pull the lizards away from Bart results in their escaping into the wild.
* NotSoDifferent: Bart tells Marge during the climax that while he knows everyone else thinks the lizards are monsters, he still loves them because he sees them as his children. Marge of course, assures him that she knows exactly how that feels and helps him protect them.
-->'''Bart:''' Everyone thinks they're monsters. But I raised them, and I love them! [[ObliviousToTheirOwnDescription I know that's hard to understand.]]\\
'''Marge:''' [[SugarWiki/HeartwarmingMoments Not as hard as you think.]]
* ParentsForADay: Bart, hence the title.
* RunningGag: Homer falling downstairs into the unlit basement.
* TheScapegoat: When Bart asks for a go with Nelson's gun, he says he'll be pleased to have Bart's fingerprints on it.
* SkewedPriorities: When Nelson gets enough tickets to win an easy-bake oven or a BB gun, he replies with this gem:
-->'''Nelson:''' Hmm... hot food is tempting, but I can't say no to a weapon.
* SuckECheeses and NoodleIncident: According to the sign outside, the Family Fun Center was once seen on the FOX reality special, "When Disaster Strikes 4." Viewers aren't given more information on how and why the Family Fun Center was featured there.
* SummonBiggerFish: Done 4 times in a row. After Bart releases the lizards to prevent them from being killed, Skinner warns him he has no idea what he has unleashed... and later changes his tune because the lizards wiped out the pigeon population, which the town considered a plague.
-->'''Skinner:''' Well, I was wrong. The lizards are a godsend.
-->'''Lisa:''' But isn't that a bit short-sighted? What happens when we're overrun by lizards?
-->'''Skinner:''' No problem. We simply unleash wave after wave of Chinese needle snakes. They'll wipe out the lizards.
-->'''Lisa:''' But aren't the snakes even worse?
-->'''Skinner:''' Yes, but we're prepared for that. We've lined up a fabulous type of gorilla that thrives on snake meat.
-->'''Lisa:''' But then we're stuck with gorillas!
-->'''Skinner:''' No, that's the beautiful part. When wintertime rolls around, the gorillas simply freeze to death.
* ThisIsUnforgivable: Marge's reaction upon learning Bart shot the bird.
* WhamLine: When the eggs are hatching, we get this from Homer...
-->'''Homer:''' I see a horn!
* WingPull: Just when Chirpy Boy and Bart Jr. look like they're going to be sent hurdling off a building, it turns out they have gliding membranes like [[https://en.wikipedia.org/wiki/Draco_volans flying dragon lizards]], which allow them to parachute down unharmed.
* YourApprovalFillsMeWithShame: Nelson inflicts this on Bart.