This was the first film of John Hughes' three picture fifty-million-dollar contract with Fox, which produced Baby Day's Out, 'Miracle On 34th Street', and 'Home Alone 3 (1998), all of which were box office failures.
Verne Troyer, who's uncredited in the film, plays the stunt baby Bink for several major shots including the construction site. For other shots, a robotic stunt baby was used.
During the zoo visit one of the men grab Baby Boo's shoelace while Baby Boo is in the gorilla cage. The man has half of his body through the bars which is impossible, then in the next shot only his head and arm are through the bars.
During the zoo visit, all three men sustain serious injury. In the next scene - the construction scene - they all seem fine. In the final scene with them, they are icing hands and other body parts and Eddie is walking as if in pain.
Eddie: [Baby Bink just got away from the villains again after many times, but this time by crawling into a small sewer tunnel]
No problem, fellas. It ain't a hole. It's a tunnel. And what's every tunnel got?