Alexander and the Terrible, Horrible, No Good, Very Bad Day (2014)

In the scene where a teacher hands a guinea pig to the actor, the actor was instructed on how to hold the guinea pig prior to shooting.

In the scene where an alligator is in the living room near the front door, the alligator was brought in by four trainers. A thin strip of black tape was kept on his snout the entire time.

In the subsequent scene where the alligator walks into a pool, the alligator was placed near the pool.  The trainer tugged on a waist cable connected to the alligator and he walked towards the pool and entered. The alligator swam for a minute or two and then was retrieved by the side by his tail. Trainers strapped a float device under the alligator to get him to float. One trainer entered the pool and held the cable. The trainer pushed the alligator into frame.  The pool was heated and salt was used instead of chlorine.

In the scene where the actor holds a baby kangaroo and we see various exotic animals in the background such as a cockatoo, emu, owl and wallaby, the pens and trailers were located very close to the set. Animal handlers were onsite and just off camera. Animals were returned to their trailers right after filming.

In the scene where the kangaroo hops around in the neighborhood and in the scene where he kicks an actor, this was done in post-production through CGI.

In the scene where the guinea pig is on a surfboard and eating a cupcake, a trainer sat the guinea pig on the surfboard. The guinea pig stayed still on the board while they filmed. The trainer occasionally placed a small amount of food in front of guinea pig in order to get him move slightly.

Production added a bit of pink cake frosting around the mouth of the guinea pig. The trainer tested the frosting to check its consistency and its safety. The guinea pig never ate the frosting.