The ape performances were coached by off-screen trainers using signals to communicate with them. This made shooting more than two chimps at once difficult, so high-tech editing was used to multiply the number of apes in the frame. And since they couldn't always follow the script perfectly, the apes' reactions were cataloged and often edited together to create cohesive scenes. Regarding the unpredictability of the apes, co-executive producer Tim Burns noted, "They're a comedy writer's best friend. I think the stuff is funny to begin with, but there's no replacing how much funnier it is when the monkeys add their own peculiar performance style."