Learning about our senses and how they work is an important part of a child's education. Stinky science experiments are not only a useful way to teach about the sense of smell but can also really pique young students' interest. There are lots of different stinky science experiments kids can perform, from learning about the relationship between bacteria and smell, to growing smelly mould.
This quick experiment can be a fun way to introduce the topic of olfaction. Collect a selection of strong-smelling items, such as lemon, vinegar, ginger, garlic, perfume-soaked cotton balls, moth balls and pencil shavings, and place each item in a separate container. Give each student the chance to have a good whiff of each item while blindfolded. Ask if the student recognises the smell, if it is good or bad and whether he has any memories related to any of the smells.
This experiment teaches students about how smells travel through the air. Place a selection of strong-smelling items in sealed containers at one end of the room and ask students to take turns sitting about 20 feet away. Open the first container and time how long it takes for the student to smell what is in the container. To determine how many feet per second the smell travels, divide 20 by the amount of time in seconds that it took for the student to smell the item. Repeat the procedure with the other containers.
Odour and Bacteria
This experiment explores the relationship between bacteria and bad smells. To do this, students should find the smelliest sneakers they can and compare the bacterial content in their shoes to other items, such as the classroom door handle, a pencil case and the bathroom sink. Students need to note whether the surface being tested looks dirty or clean, then take a swab and transfer it to a labelled Petri dish. After one week, students will be able to see which surfaces have the most bacteria and if this relates to whether that surface appeared clean or dirty.
Most students will have seen mould on bread at some point; this experiment encourages them to examine it a little more closely. Instruct students to sprinkle a little water on a piece of bread then place it in a sealed container in a dark, warm place. Within a couple of days students will start to see mould growing. The mould can then be examined under a microscope and extra research will allow students to name the specific parts of the mould they can see.