NJ Core Curriculum Content Standards:

5.1, 5.5

Objectives:

Students will learn some of the different ways animals sense their environment and these senses are different from human senses. Students design animals based on the descriptions given and discuss ways animals could potentially sense their environment. This lesson was done with a 7^th grade life science class.

Materials:

Dolphin Skull

Madagascar cockroaches

Octopus (purchased at the supermarket)

Bat Slides

Lesson:

The lesson can begin by asking the students what are the five senses.

In groups of four, students are asked to discuss and draw an animal based on the descriptions given in the accompanying overhead. The animal can be make believe or the students can try and guess the real animal. After the students give their suggestion the teacher can reveal the real animal.

Animal 1 – a bat

Bats are nocturnal but they are totally blind. They use echolocation to “see” at night. The animal makes a high frequency sound that hits an object and bounces back to the animal. These “echos” help the animal avoid objects or locate prey. Bats have very large ears relative to their body, which help them capture as much sound as possible.

Animal 2- an octopus

Octopus has chemoreceptors on their suckers, which allow them to taste the food that they eat. Octopuses and squids register smell in small pits located beneath the eyes. Octopus are color blind. They have a beak that helps them shred their food before they eat it.

Animal 3- an insect

Insects have receptors on their antennae that allow them to smell the world around them. They have chemoreceptors on their feet and jaws, which allow them to taste their food. Cockroaches can detect movement with their hairs on their backside.

Animal 4- a dolphin

Dolphins can hear because their lower jaw can detect sound. Sound traveling through water enters the head toward the rear of the lower jaws, and travels through a fatty channel directly to the inner ear. Dolphins can hear frequencies up to 100,000 Hz. Humans can only hear between 20 and 20,000 Hz. They use echolocation or sonar to “see” under water but they also have excellent vision with their eyes. They have eyes on the sides of their heads that allow them to see in front and in back of them. The melon is the forehead of the dolphin. It is the organ that the dolphin uses to produce sound.

The teacher leads a discussion of these animals emphasizing how each animal senses their environment. Before having the students design their own animal, ask them how humans smell, taste, hear or see their environment. Ask the students if all animals have tongues to taste with, noses to smell with, eyes to see or ears to hear. This will help the students understand that although animals might have the same senses as humans, the anatomical structures for sensing the environment might be different. For example, cockroaches smell with their antennae and bats “see” with their eyes.

Having hands-on material like insect models or live insects to show the students really helps with this lesson. This is what makes it more than just a lecture. Frozen octopus or squid can be purchased at an Asian food market or at many local supermarkets. The Madagascar hissing cockroaches were borrowed from the Math and Science Learning Center. These were easy to transport and large enough for the students to see without magnifying glasses. The dolphin skull and slides were also borrowed from the Math and Science Learning Center. There are many excellent we sites on animal senses that the students can review or teachers can explore for pictures and other teaching material. Below are just a few.

http://faculty.washington.edu/chudler/amaze.html

http://ebiomedia.com/gall/eyes/octopus-insect.html

Self-Assessment/Reflections:

When planning future lessons, I knew I needed to give myself more time to bounce ideas off the teachers and get the material together. The students really enjoyed the hands-on material but I felt that they did not grasp the concepts as well as I would have liked. It turned out to be more of a show and tell activity and it was hard at times to get the students attention.