More Than Just Dust Bunnies

Download This Lesson: More Than Just Dust Bunnies

Brief Description: Students will learn about dust and its components using slides and microscopes. After reading about the history of the microscope students will look at dust, small organisms in dust and dust allergies using wet and dry slides. Using pictures and graphs students will present their findings.

Focus Areas:  Pest Identification; Science

Focus Skills:  Preparing slides, using a microscope, collecting and recording data

Level of Involvement:  MAXIMUM

Objectives

•  To discover that dust contains living organisms
•  To understand that some people are allergic to the fecal material of these organisms
•  To recognize the need to prevent dust from accumulating

Essential Question

Why should areas be kept free of dust?

Essential Understanding

Background

The inventor of the microscope, Anton van Leeuwenhoek, reported in 1694 that mites live in dust. Now, more than 300 years later, it is an established fact that dust mites can be found in house dust all over the world. Dust mites are not insects but are more closely related to spiders and ticks. There are two common dust mites, the American house dust mite (Dermatophagoides farinae) and the European house dust mite (D. pteronyssinus). Due to their very small size, these dust mites are not visible to the naked eye. They live in bedding, couches, carpet, stuffed toys and old clothing. Dust mites feed on the dead skin that falls off the bodies of humans and animals and on other organic material foundwhere they live.

Habits and Habitats

Dust mites do not live in air ducts in homes. Many people spend much time and money cleaning the air ducts to reduce dust mites. This is not necessary because dust mites need about 70 percent relative humidity or higher to live, and they need food. Areas where people spend much time, like a bed or a favorite plush chair, are prime sites for dust mites. The top part of mattresses containing fibrous material is a favorite place for dust mites during warm and humid times. The deeper parts of mattresses may provide protected areas for the dust mites during unfavorable conditions. Clothing is used by dust mites as a means of transportation from room to room or even from house to house.

Vocabulary

allergic reactions – Physical symptoms, which may include sneezing, itching, skin rashes, caused by abnormally high sensitivity to certain substances such as pollens, foods, or microorganisms.

allergen – A substance, such as pollen, that causes an allergy.

arachnids – The anthropod class (invertebrate animals with jointed appendages) that includes spiders, mites, ticks, and scorpions.

dust bunny – A clump of dust commonly found under beds, chairs, and couches.

Challenge:  Search for animals in a dust bunny!

Logistics

Time:  45 minutes

Group size: as many as your supply of microscopes can accommodate (3 to a scope maximum)

Space: an area to accommodate microscopes

Materials

• microscopes
• slides (minimum of 6 per group)
• slide covers
• eye droppers
• water for wet mount preparation
• dust from several locations and containers for each
• computer with Internet access
• overhead projector
• Overhead Control of Dust Mites *
• Assessment for a Scientific Drawing *
• Assessment for a Graph *

* single copy provided

Preparations

1.  Gather materials as listed above (except dust)
2.  Set up lab stations with materials

Important

Before beginning this activity, be sure that neither you nor anyone in your group is prone to severe allergies to dust. Send notes home asking parents to give permission for their child to participate in this activity.

ELA = English Language Arts,   HE/PE = Health Education and Physical Education,    MA = Mathematics,    SCI = Science,   SS = Social Studies,   VPA = Visual and Performing Arts

** Alignment possible only if lesson extension is done