1. The pun is "investigator". It plays on the similar sound between "investi-gator" (a person who investigates) and "gator" (short for alligator). The joke is that an alligator in a vest is an "investi-gator".
2. The pun is "took the words right out of his mouth". This phrase usually means to say exactly what someone else was about to say. Here, it's literal: the dog chewed the dictionary, so the owner physically removed the printed words from the dog’s mouth.
3. The pun is "kicked out of the library for taking too loud". It plays on "taking too loud" sounding like "ticking too loud". A clock makes a ticking sound, so the joke is that the clock was expelled for being too noisy with its ticking.
Parent Tip: Review the logic above to help your child master the concept of puns worksheet.