Silkworm Life Cycle

Known for the silk thread they produce to form their cocoons, the silkworm is the larvae stage for the Bombyx mori moth. As an insect that undergoes complete metamorphosis, it has 4 stages of development.

Eggs

The eggs are very tiny and are usually laid near the end of summer or early fall. They remain dormant until spring or when warmth stimulates a spring season environment. It takes the eggs about two weeks to hatch after they are activated.

If you want to store Silkworm eggs, be sure to put them in a fridge right away (don’t freeze them). Keep them near the warmer part of the refrigerator.

Larvae (Silkworm)

silkwormsNewly hatched silkworms are small (1/8 inch), hairy, and eat tender mulberry leaves. The hair gets shed when they go through their first of five growth stages called instars.

You can tell an silkworm is about cross an instar stage because it will hold its head up in the air. Its important to not touch or disturb the silk worm as its transitioning between instar stages. It will then shed its outer layer of skin. After each instar the silkworm is able to eat tougher mulberry leaves and will be bigger.

After 5 instar stages, the Silkworm will encase itself with a silk cocoon.

Pupa (Cocoon)

Silkworm cocoonSilkworm cocoons will be shades of white, cream, and yellow. They will have a glistening shine because of the silk they are made from.

After 2 weeks, the silkworm releases an enzyme from its head that dissolves the silk. It then emerges as an adult moth.

Adult (Moth)

Adult: Bombyx Mori mothSilkworm moths (Bombyx mori) do not eat or drink. They crawl around but do not fly. Females have a larger abdomen and are not very active. Males have much larger antennae and will vibrate its wings rapidly as it seeks a female.

After reproduction, the male moth dies. The female will lay eggs within 24 hours and die shortly thereafter.

Interesting Silkworm facts

Due to hundreds of years of domestication (providing abundant food and pampering them), Bombyx mori (silkworms) do not crawl away in the pupa stage and can’t fly in the adult stage.

Silk is harvested by killing the pupa (by heating or pricking with a needle) and then unwinding the thread of silk, which can be half a mile long.

The entire life cycle only takes a couple months.

The Bombyx mori silkworms were originally domesticated in China where the secret to producing silk was closely guarded for centuries but was leaked around 200 BC and eventually was also produced in India and Europe.

Silkworm pupae are a delicacy eaten in China.

Where you can buy Silkworm Supplies

Silkworm food

25 live silk worms

25 silk worm eggs

Silkworm life cycle model

Where you can learn more about Silkworms

Detailed life cycle

History and general information

Another step-by-step life cycle

Glitter Tattoos Profit Calculator

What should you Charge for Glitter Tattoos

Glitter Tattoo Station
A Glitter Tattoo Station is great for a bulk supply of Glitter, Glue, and initial 300 tattoo stencils. This initial investment can seem like alot, but if you price the glitter tattoos correctly, you can turn it into a great fundraiser.

If you’re at a fair or someplace where prices are generally high $4 to $6 is a good price range. If this is for a low budget event, then $1 to $3 would be a good price range.

Costs Breakdown

If you purchase from HeathScientific.net the approximate prices would be:

  • Glitter Station: $300
  • Glitter Tattoo Stencils: $3 (for 10 stencils)
  • Shipping: $13

Keep in mind that the Glitter Tattoo Station has enough glue and glitter for 1,300 tattoos but only enough stencils for 300. You will only have to purchase additional stencils to make 1,000 more tattoos.

Online Glitter Tattoo Station Calculator

  • Glitter Station: $300.00

Disclaimer: This calculator should not be taken as a guarantee for sales or revenue.

Where you can get supplies

For stencils, glue, glitter, or the full station – HeathScientific.net sells all of those products at very fair prices.

How to activate and reuse Glacial Heat

Activation

Glacial Heat, commonly known as hot ice, is easy to use.
Bend or flex the metal disc in the Glacial Heat pack. Instantly, ice will form on the disc and spread through the pack. You will feel the pack get warm. It should stay warm for at least half an hour.

The pack remains frozen at room temperature until you prepare it for reuse.

Reuse

To reuse the pack, put it in boiling water for about 10 minutes. I recommend medium heat on your stovetop. You might smell a slight odor of plastic–that’s okay. Flip the pack in the water while heating to avoid melting the rubberized cover.

Take the Glacial Heat pack out of the water after all the crystals are gone and let it cool. Once it cools completely, it is ready for use.

Video instructions

The science

Curious about the science behind the Glacial Heat pack? Check out these links:

Steps to a Successful Science Fair Project

Science fair project

8 steps to a successful science fair project. Photo by terren.

  • Did the student learn something from the project?
  • Did the student follow the scientific method to complete the experiment?

If the answer to each these questions is yes, then the student was successful. Let me give you 8 steps to a Successful Science Fair Project.

  1. The first and most important step is the Selection of a Topic. The topic should be of interest to the student and selected prior to designing the science fair project. Example topics could include oceanography, basketball, ballet, sharks, micro-organisms, magnets, etc.
  2. The second step involves some creativity. At this point, you must ask a question about your topic that can be answered in an experiment. For example, if the topic was micro-organisms, the question might be, “What surface in my house contains the most bacteria?”
  3. Next, you must research the topic and discover background information that will be useful for your experiment. In order to answer the question above, you would need to know how to grow bacteria, how to take samples, optimum growth temperature, safety procedures, where do bacteria grow, etc.
  4. Then, you need to take the question from step 2 and reword it, so that, a purpose statement is created. From the question we created in step 2, our purpose statement could be, “The purpose of my experiment is to determine which surface in my home contains the most bacteria.”
  5. Now take the purpose of your experiment and develop a hypothesis. The hypothesis is an educated guess as to the outcome of your experiment. Your hypothesis could be, “My hypothesis is that the toilet seat has the most bacteria.” Don’t ever change your hypothesis. Your hypothesis is based on your research and knowledge. If the experiment disproves your hypothesis, that is OK. An incorrect hypothesis does not make an unsuccessful project.
  6. Design the experiment. This is where most people start. Never start with the experiment, because many times the outcome is know. Learning and using the scientific method is the most important part. During this step, you will determine the materials needed, explain the procedure, collect data and record results.
  7. Draw a conclusion. The conclusion is simply, “Was my hypothesis correct or incorrect?” Your conclusion might be, “In conclusion, my hypothesis was incorrect, the kitchen sink was actually the area that contained the most bacteria.”
  8. The final step is to make an attractive science fair display. You should have label headings, such as, Purpose, Hypothesis, Materials, Procedure, Data/Results, Conclusion. Display part of your experiment. If parts of the experiment are not able to be displayed, use photos that explain your procedure and results.

Teaching Electricity and Simple Circuits to Elementary Students

Circuits in the elementary classroom

Teaching circuits to students

Electricity can be a complex and imposing topic to present to your students. Before we talk about circuits, let’s go over a few definitions:

  • Load – A device that does work or performs a job (i.e., the light bulb in our circuit).
  • Electrical current – The flow of electrons from an area of high concentration (“a lot”) to an area of lower concentration. *Note: the negative side of the battery has a high concentration of electrons.
  • Electron – A negatively charged particle that orbits the nucleus of an atom.
  • Generator – A device that converts mechanical or chemical energy into electricity. Wind, water or an engine can power a generator.
  • Electrical circuit – An electrical path that is closed (all parts connected), allowing the electricity to return to the original source (the battery).
  • Parallel Circuit – A circuit in which the components are connected like a ladder. This circuit splits the voltage equally to all of the components.

Simple Circuit

Creating a Simple Circuit

  1. Place a “D” cell battery in a battery holder. The battery holder will allow you to attach wires with alligator clips to the positive and negative ends of the battery.
  2. Now, screw a small light bulb (mini lamp) into a lamp holder. Like the battery holder, the lamp holder will allow you to attach alligator clips to the light bulb (your load).
  3. To complete the circuit, you will need two wires with alligator clips. Use one wire to connect the negative side of the battery to the lamp holder. It does not matter which side of the lamp holder the wire is attached. Connect the positive side of the battery to the lamp holder using the second wire. This wire will attach to the opposite side of the lamp holder. The light bulb should be lit.

Remember, the voltage of the battery and light bulb should be similar. If the battery voltage is too much larger than the voltage capacity of your bulb, the bulb will burn out. A “D” cell battery provides 1.5V.

Simple Circuit with Switch

Adding a Knife Switch to a Simple Circuit

We will modify our simple circuit described above to complete this task.

  1. Disconnect the alligator clip that is attached to the negative side of the battery and re-connect it to one side of the knife switch. Make sure the knife switch is in the upright position.
  2. Take a separate wire and connect the negative side of the battery to the knife switch. Notice that the light is off.
  3. Lower the arm on the knife switch to connect the circuit and light the bulb.

The knife switch allows you to discuss breaking the circuit and stopping the flow of electrons.

Heath Scientific provides a kit called “Making Circuits Simple” that includes all of the components described in this article. It’s an easy, all-in-one kit to demonstrate circuits to your students.