Incorporate music into one of your daily bug lessons by exploring the symphony of sound produced by different kinds of insects. Take the students outdoors on a nice day to listen for the sounds produced by bugs, and then based on what they hear, have them try to guess what kind of bug made the sound. If you'd rather stay indoors, have the students brainstorm about which bugs make noise, and what each sounds like. For extra fun, assign the preschoolers each with a kind of bug sound, like a buzzing bee or a chirping cricket, and then have them croon a song like "The Itsy Bitsy Spider," using only the sound they were given.
Don't expect a preschooler to grasp advanced entomology subjects, but do introduce them to the field with a day of scientific exploration of bugs. Head outdoors if you can; otherwise, provide some bug samples for students to investigate. Talk about the different parts of insects and other bugs, the things they like to eat, and other basic characteristics that preschoolers will be able to understand. Give each student a magnifying glass to examine the specimens, if you chose to remain indoors, or provide him with a net and a jar for bug collecting in an outdoor setting.
Use the overall bug theme as a way to introduce the preschoolers to basic mathematical concepts like addition and subtraction. If those methods are still too advanced for the age group you teach, simply focus on numbers and counting. For instance, count the number of legs on an ant or the spots on a ladybug's back. Give the spotlight to certain numbers that will appear frequently in your exploration of bugs, like the number two, which is often seen in pairs of antennae and wings.
Storytelling is an important step towards the preschoolers' eventual literacy, so focus on some bug-themed stories to read to the class. Take time to discuss the lessons demonstrated in the books, like the "Ant and the Grasshopper" fable that teaches the value of hard work. Encourage the kids to come up with their own bug-inspired stories by drawing pictures and dictating to an adult what is happening in each illustration. The students can present their works, or you can simply display them throughout the classroom.