Things You'll Need
- Stopwatch
- Calculator
Instructions
Position the rat so you can look down on it. If needed, use a piece of food to keep the rat busy but relatively still.
Watch the rat's ribcage expand and contract. You will be counting the number of times the ribcage expands to its full capacity.
Start the stopwatch. Count each time you see the ribcage expand. Stop counting after 15 seconds have elapsed.
Multiply the number you counted by 4 to calculate the number of breaths per minute.