Thin pickings: When told by her mum that she can't have an outfit because it makes her look like a streetwalker, Buffy protests "but like a thin streetwalker." Now come on. Is there really anything out there that could make Buffy look fat? Even a flour sack would look good on her.

Horror movie homage: The plot of this episode makes a lot of movie references. Most obvious is Alien, another film where vile monsterspawn leap still wet from eggs to infest people's bodies. The scene where the egg-creature whips around Buffy's bedroom is particularly reminiscient of a scene in Aliens, where Ripley only just manages to protect a little girl from an alien under the bed.

The creatures' taste for clamping the back of the neck is similar to the Tingler of William Castle's 1959 film of the same name - which played in theatres with seats rigged up to buzz people's bottoms and make them scream. The egg-evil's "neural clamping" also parallels the Star Trek: The Next Generation episode Conspiracy, in which back-of-neck neural parasites infiltrate Starfleet command.

Finally, the calm and collected subservience of the Bezoar-controlled people strongly calls to mind the classic '50s chiller Invasion of the Bodysnatchers. It was remade in 1978 with Leonard Nimoy - Spock from Star Trek - as one of the leads.

No diddy demons to dandle: The whole egg parenthood business prompts Angel to reveal to Buffy that he, like all vampires, can't have children. Well, it makes sense - he is dead after all.

But, without wanting to give too much away, can he really be 100 percent sure?

Cheating as a road to success: On learning that Xander hard-boiled his egg, Giles admits his tactic has a certain "Machiavelian ingenuity."

Machiavelli lived in Italy in the fifteenth century and is mostly famed for writing a book called The Prince, about how to get into power and stay there. Lying, cheating and cruelty were all fine in Machiaveli's eyes, so long as they got the job done. That doesn't sound too much like our cuddly cheerful Xander really - maybe Giles was being sarcastic.

Dear little dreidel: As Willow's egg is Jewish, Xander suggests she teach it "that dreidel song" instead. A dreidel is a small squarish spinning top used in the celebration of the Jewish festival of Hannukah. Children play a game with it, and sing the dreidel song, which goes:

I have a little dreidel.
I made it out of clay.
And when it's dry and ready,
My dreidel I shall play.

Oh dreidel, dreidel, dreidel,
I made it out of clay.
Oh dreidel, dreidel, dreidel,
My dreidel I shall play.

Rat kebab: Lyle and Tector Gorch seem to be either particularly cautious or particularly pathetic vampires. They can't even find themself anything better to eat than rat.

It seems that vamps can get by on sewer chicken for quite a while - as will be revealed about Angel. It also crops up in Anne Rice's Interview with the Vampire.

Tamagotchi torture: Faced with caring for her egg, Buffy confesses to having killed her Giga-pet to show how unsuited she is for the task. Giga-pets were electronic pets which consisted of an animation of a cute animal on a pocket-sized screen. The demanding cyber-critters must be fed, played with, taken to the bathroom and so on, all managed by pressing the appropriate buttons. Neglect it, and it will die.

The classic electronic pet was, of course, the Japanese Tamagotchi. When these became hard to obtain in the USA, a local company started to produce Giga-pets as a Tamagotchi rip-off. They're still going, with varieties available including the Digital Doggie, Compu Kitty and Komputer Koala.

Justice for gingers :Lyle Gorch tells his brother that he's going to "beat him like a red-headed stepchild." Where this quite common phrase comes from is unclear, but what it means sadly isn't. A stepchild would be more likely to be in for abuse, and a red-headed one, i.e. one which reminded the step-parent of their partner's former love, even more so. And everyone picks on red-heads anyway, the meanies.

Bezoar bungle: In Bad Eggs, a Bezoar is described as a "pre-prehistorc parasite." In the dictionary, it's described as a sort of stone found in the stomach of certain animals, mostly ruminants like sheep and goats, and once believed to be an antidote to most kinds of poison. Guess the scriptwriters were using their artistic licence that day.

A little light reading: Joyce is unnerved by the titles of two of Giles' books - "Bristow's Demon Index" and "Hell's Offspring". We'd love to know the publisher.

Oh no, not again! Small, but beautifully formed, Jonathan's in trouble again in this episode. This time we hear his screams as he tries to escape the eggbourne parasite, and is taken over by the mother Bezoar.

Educational standards: School ends at 2.30. Isn't that rather early?

Doing it for the fans: There's a couple of acknowlegements to Buffy's strong internet community in this episode. In the science lab during the dissection, the words Posting Board can be seen on a blackboard - a nod to the regulars on the main Buffy forum.