At one point, Wade ([Rainn Wilson]) insinuates that Clint (Elijah Wood) sneaks around like a Hobbit. Wood played the Hobbit Frodo Baggins in the "Lord of the Rings" trilogy.

The second time that Elijah Wood plays a character who fights monsters in a school. The first time was in The Faculty (1998).

The photo featured in the beginning inside Clint's (Elijah Wood) bedroom is an actual picture of Wood as a kid.

In facility manager's room is a mirror that looks like the Dharma logo, a company in Lost (2004), in which Jorge Garcia appeared.

When the police show up, Rick (Jorge Garcia) mentions the 5-0. The term "5-0" is slang to alert others to police or other authority presence. It was derived from TV show Hawaii Five-O (1968). Garcia is a regular cast member of the reboot of Hawaii Five-0 (2010).

Even though Miles Elliot played Dink and credits listed him as Dink, no one in the movie said his name at all.

Kate Flannery and Rainn Wilson were costars on the American TV series The Office (2005).

This is the second time Elijah Wood fights monsters in the school. The first one was The Faculty (1998).

When the group of survivors drives through the town of Danville, they pass a movie theater with two movie posters displayed: one for this movie with the skeletal hand holding a lollipop, the other one for A Girl Walks Home Alone at Night (2014), which was co-produced by "Cooties"-writer Josh C. Waller.