The Sneaky Simpsons References Only Hardcore Fans Spotted On Bones

Fox's long-lived procedural "Bones" always had a cheeky sense of humor. Though the show could also be deadly earnest and serious depending on what case the team at the Jeffersonian Institute was tackling, it knew how to make its audience laugh when it felt the need to do so. Almost any scene between partners, lovers, and eventual spouses Seeley Booth (David Boreanaz) and Temperance Brennan (Emily Deschanel) crackles with banter and tension, but sometimes the crimes they investigate are also so delightfully ridiculous that they end up tweaking the viewer's funny bone. 

For example: take this tiny but notable reference to another Fox program hidden deep in the background of one of the show's scenes. This reference to the even-longer-lived Fox animated series "The Simpsons" is a blink-and-you-miss-it moment, but it's a fun reference that only hardcore fans will notice if they pause the program and take a much deeper look at what's happening in the background.

During the first scene of the Season 5 episode "The Dwarf in the Dirt," Angela Montenegro (Michaela Conlin) and Lance Sweets (John Francis Daley) are seen conversing over the bones of their latest John Doe in the Jeffersonian. One can see the x-ray bed over Sweets' shoulder as they speak — and an x-ray of the skull of Simpson paterfamilias Homer Simpson eventually pops into view as the conversation goes on, his tiny brain on a stem within his large skull.

This clever Easter egg won some applause from Reddit users posting to the Bones subreddit. "I will now need to go back and watch this episode to spot it lol," said u/Duskmuse711. "I have rewatched this show at least a dozen times and have never seen this," remarked u/spaceburrito3.

But it seems, as a deleted user pointed out, that the x-ray was very purposefully placed in the background instead of being an off-the-cuff, silly sight gag. Per The New York Times, Homer's x-ray was a part of a network-wide tribute to "The Simpsons" in celebration of the show's 20th anniversary. Multiple shows airing on Fox at the time included Springfield-related Easter eggs and background gags during that week. Dan Castellaneta, who has voiced Homer since the show debuted as a sketch on "The Tracey Ullman Show," even appears in "The Dwarf in the Dirt" as Officer Novarro.

Perhaps unsurprisingly, at least one "Bones" star has returned the favor and shown up on "The Simpsons" in a guest star capacity. Per IMDb, you can hear Emily Deschanel voice herself in Episode 1 of Season 30, "Bart's Not Dead." David Boreanaz has, meanwhile, voiced himself for "Family Guy" and "American Dad!".