What your Preschooler will Learn from this Preschool Biology Activity:

That they have fingerprints

That fingerprints are individual to them

What fingerprints look like

What you Need for this Preschool Biology Activity:

A magnifying glass

Paper

Ink Pad

Crayons

Markers

What To Do:

Step one: Have your preschooler inspect their fingertips with the magnifying glass. Point out the fingerprints. Point that that the swirls may be circles, loops or other shapes.

Step two: Have your preschooler inspect your fingerprints. Ask them if your fingerprints are different than theirs. If they're old enough, have them draw the fingerprint shapes in their scientific journal.

Step three: Trace around your preschooler's hand using your crayons or markers onto the paper.

Step four: Press their fingertips into the ink pad, and press their finger tips onto the hand that you drew. Match up the fingers. For example, make sure the thumb of your hand has the thumb print on it. You may need to do the fingers one at a time.

Step five: Have your preschooler decorate the mother's day card.

Step six: Give your mother's day card to a mother or grandmother.

Why Decorate a Mother's Day Card with your Preschooler's Fingerprints?

Fingerprints are caused by the movement of the amniotic fluid that surrounds babies before they're born. This is why identical twins don't have identical fingerprints. As your baby develops inside of you, your movements, how you moved during your pregnancy helped determine what your child's fingerprints look like. Since fingerprints don't change, but a child's hand size will, getting a special mother's day card decorated with your preschooler's fingerprints is a wonderful gift and memory you can always cherish.

Hi! I'm Theresa Halvorsen, the preschool science and nature writer for Preschoolrock.com. I have twin boys and am blown away by their fascination with preschool science and how the world works around them. I am always looking for fun and simple science activities so preschoolers can learn about science and the natural world. Please contact me with any suggestions, ideas or questions you have about this site.

Helpful Tips for Parents

• Science supplies don't need to be purchased. Vinegar, baking soda, cornstarch, salt, food coloring, and dish soap cover most preschool science experiments adequately.

• Visit science museums, planetariums, and nature centers regularly. Real encounters with scientific environments are more motivating than any experiment at home.

• Give children real tools: a real magnifying glass, real measuring cups, a real thermometer. Toy versions deliver less sensory and intellectual feedback than actual instruments.

• Integrate science into daily routines: cooking (chemistry), gardening (biology), building (physics), weather watching (meteorology). A science-rich home requires no special equipment.

Frequently Asked Questions

What everyday household materials are best for preschool science?

The essential preschool science pantry: baking soda, white vinegar, cornstarch, salt, sugar, food coloring, dish soap, and water. These materials enable: acid-base chemistry (baking soda + vinegar), non-Newtonian fluids (cornstarch + water = oobleck), color mixing (food coloring), surface tension (dish soap), crystal growing (salt and sugar), and density experiments (sugar solutions). Beyond kitchen supplies: magnets, a flashlight, a magnifying glass, and ice are the other essentials. The best science lab is an accessible kitchen shelf.

How do I build a child's science confidence when they get frustrated by unexpected results?

"Unexpected" is the word to use rather than "wrong" — in science, results that don't match predictions are the most interesting. "The result was different from what we expected — that means we discovered something! Let's figure out why." This reframe makes the unexpected result a success rather than a failure, because it produced a question worth investigating. Science confidence is built by treating all results as valid data, never as failure.

Related reading: See also our nature walks guide and our color mixing science for more ideas on this topic.

🎓 Skills Your Child Will Develop

• 😌 Patience & Delayed Gratification — Experiments with delayed results — growing plants, watching crystals form, tracking weather — teach children to wait for outcomes rather than needing immediate feedback, a skill that predicts academic and life success.
• 🔍 Observation Skills — Paying close attention to what happens during an experiment — noting colors, textures, movements, and changes — builds the observational precision that all scientific and analytical work requires.
• 🔬 Scientific Method — Even a simple experiment teaches the predict-test-observe cycle that is the foundation of scientific thinking — and preschoolers who internalize this process approach problems with genuine scientific confidence.
• ⚖️ Cause & Effect Understanding — Seeing that one action reliably produces a specific result builds the logical framework children use in mathematics, reading (one event causes another in stories), and everyday reasoning.

Does your preschooler know they have fingerprints? Do they know their fingerprints are individual to them—no one else has fingerprints like them? Are you looking for a fun activity that combines science and a mother's day present?