You’ll need a set of pre-made petri dishes with agar (the stuff bacteria grows on), glow powder, an invisibility pen WITH a small black light built in, some bags, cotton swabs, cups, bags and safety seals. Because I LOVE creating mystery for my kids I had everything ready for them to explore on our first snow day of the year. We were going to EXPLORE the INVISIBLE! Which of course grabbed my boys interest (ages 8 & 6) and we were off to a good start!
Alright, most of you know that I’m a science nut. I majored in Biology in college and other than Genetics my all time favorite class was Microbiology (yes, the study of bacteria). Weird I know – but I LOVED it!! In fact I loved it so much that I got paid to make all of our agar broth and petri dishes for the semester for the entire college!!!
I won’t bore you with everything I learned but introducing kids to microorganisms is an important and exciting lesson for them. From the time our kids are preschoolers we teach them about germs and washing their hands.
As they get older we talk about virus, vaccines, mold, and other bacterial illnesses. On Amazon the other day I found that you can actually purchase a 10 pack of pre-made petri dishes with agar in it. How do you use this? Simply use a swab (like a qtip) that is provided and swipe any surface you are checking for bacteria – doorknobs, countertops, floors, toilets, etc.
Slowly swipe the swab in a zig zag manner across the top of the agar in the petri dish and wait for it to grow! Any growth you see will be some sort of microorganism – most commonly a bacteria. Your children can VISUALLY watch the growth of bacteria! It is no longer an invisible entity to them. They can monitor how rapidly the bacteria grows even throughout the day! If you have a microscope your child can carefully spread some of the bacteria onto a slide and look at it under the microscope.
There are SO many lessons you can pair with this activity depending on the age of the child. You can have them wash specific areas and see if they cleaned it properly. You can hypothesize what is the dirtiest surface in your house. You can even swab their hands or toes to see what is growing! (although be prepared for some pretty nasty possibilities!!
First we discussed what things in life are very real but seem invisible to us – the wind, germs, emotions. We started with germs and the importance of understanding that not all germs are bad and also how important it is to wash our hands a LOT because bad germs can easily spread. (It also helped that little sister has been very sick so we referred to her picking up germs.)
We did this in college and my lab partner had tons of yeast in between his toes! ICK!) You can try to determine what TYPES of bacteria you have found. Did you know that each bacteria has a specific odor? I do NOT suggest having your children sniff the bacteria!!! It is just an interesting note I realized in college for my lab finals!! We were given two vials of unknown bacteria and had 2 weeks to determine what was in our vials! I noticed that each vial had a very specific odor and compared it with the vials of my classmates. What can I say – I am a very hands-on learner!! 🙂