Mealworm Senses

In this lesson, students carry out several investigations to analyze the behavioral responses of mealworms to different types of sensory stimuli in order to evaluate how the external structures of insects allow them to receive information through their senses. 

• All animals, including humans, have senses— how animals get information about the outside world.  
• Senses are important for all animals because senses are how animals interpret their environment, which is essential for survival.
• Not all animals use their senses in the same way. Animals have senses that are suited for their environment, and help them survive in their particular environment.
• Animals are systems because they are made up of smaller parts, including sense receptors, that interact and work together to help the animal survive. . 
• Organisms have different kinds of behaviors, depending on whether the behavior is learned or innate.
  
  

• How does an animal’s structures relate to how it senses its environment?
• How do our ears gather information about sound from the environment?
• How do eyes gather information about the environment?
• How does the catfish’s sense of taste help it survive in its environment?
• How is the eyesight of mealworms different from the eyesight of people, and how is this difference related to the mealworm’s environment?
• How does a mealworm’s structures help it sense its environment?  
• How is the information gathered by an animal’s senses part of the system?
• What happens to that information once a sense receptor has gathered information from the environment?  
• What happens once the brain receives the information?  
• How do these inputs of information impact the animal?
  
  

Misconception: Humans only have 5 senses.

Fact: Humans have more than 5 senses, but the 5 most commonly taught at this age are seeing, hearing, tasting, touching, and smelling.

Misconception: Individual organisms can develop adaptations in response to the environment.

Fact: Adaptations are developed over many generations.

Misconception: An organism can choose an adaptation.

Fact: Organisms cannot choose adaptations. They are specific traits that are passed down from generation to generation. They are shaped by the environment.

Adaptation: a trait that helps an organism survive in its environment

Behavior:  an organism’s response to a stimulus

Brain:  the part of the body that interprets (makes sense of) all of the information the senses receive

Innate behaviors:  those behaviors that an organism is born knowing how to do

Sense: how animals get information about the outside world

Stimulus : anything in the environment that causes an organism to react

Senses Affect Behavior

Senses play an important role in an animal’s ability to survive because they affect an organism’s behavior. A behavior is an organism’s response to a stimulus. A stimulus is anything in the environment that causes an organism to react.

The way an animal processes information from the environment and then acts on it can be understood by thinking about the senses as part of a system. Remember that a system is a set of connected, interacting parts that form a more complex whole.

Systems have inputs and outputs. Inputs are what are received by the system. The information gathered from a sense is an input. For example, mealworms use their legs and antennae to gather inputs of information about the feel of the environment. They use their eyes to sense the brightness of the environment.

Once an animal’s senses have gathered information from the environment, the senses then pass that information to the brain. The brain is the part of the body that interprets all of the information the senses receive. It is often found in an animal’s head. The brain interprets the information so the animal can make sense of the environment at that moment. The information can also be stored as memories.

Outputs are what are sent from the system. The behavior that results from the brain’s interpretations of the information is the output. When a mealworm senses that food is nearby, it moves toward the food. If it senses bright light, it moves away from it. These movements are outputs.

Kinds of Behavior

Animals respond to the information processed by the brain in different ways. Behaviors can be learned or innate. A learned behavior is a change in behavior based on experience. In other words, it has to be taught. Innate behaviors are those behaviors that an organism is born knowing how to do.

There are two kinds of innate behaviors: reflexive and instinctive. A reflexive behavior is an involuntary, immediate response to a stimulus. Jumping when you hear a loud noise is an example of a reflexive behavior.

An instinctive behavior is a more complex response to a stimulus. Instinctive behaviors often relate to those necessary for an organism’s survival, such as finding food, caring for young, and avoiding predators. For example, birds build nests instinctively. They do not have to be taught how to do this. Mealworms instinctively use their senses to seek out food and dark, damp areas that protect them from predators. They do not have to learn these behaviors.

Using Senses to Survive

The mealworm’s behaviors of finding food and avoiding predators are essential to the mealworm’s survival. Without them, mealworms would not be able to complete their life cycle.

The mealworm’s life cycle has four stages: egg, larva, pupa, and adult. Mealworms are the larva stage of the darkling beetle. A larva is a young form of an adult insect.

The mealworm uses its senses to avoid predators and eat as much food as it can. It needs enough food to get it through the next stage, called a pupa, because the mealworm pupa does not move or eat. All of the pupa’s energy is used to change its body from a mealworm into an adult darkling beetle.

In this lesson, students analyze how animals have different structures that allow them to gather sensory information about their environment and then use that information to influence their behavior. Specifically, students make observations about the mealworm’s physical structures and how it behaves when exposed to different stimuli, specifically touch, air, food, light, water, and odor. Students collect and analyze data to analyze the relationship between a mealworm’s physical structures, its senses, and its ability to find and eat food.