How to Track Your Hedgehog's Wheel Activity Using a Bike Computer

Ever wondered how far your hedgehog runs on their wheel at night? You can track your hedgehog's midnight miles with a simple bike computer!

Why?

• Curiosity: Some hedgies run a ton, while others prefer a short walk around the block. Where on the spectrum does your hedgehog fall? Think this is cool? Try a nightly timelapse!
• Research: The more we know about hedgehogs, the better we can care for them. Knowing how much your hedgehog runs can help inform husbandry decisions moving forward. 
• Health Check: Hedgehogs are good at hiding illness. A sudden drop in wheel activity could be your first clue that something's up. 
• Wheel Maintenance: Checking the bike computer/wheel logger regularly means you're more likely to spot any wheel issues before they become a problem.
• Bragging Rights: Tell your friends that your potato sized pet out-runs them every night, with verifiable facts.*
  *depending on how active your hedgehog is and how active your friends are

How does it work?

Bike computers are pretty straightforward. They have four main parts:

1. The computer itself
2. A mount for the computer
3. A wired sensor
4. A magnet

The computer counts how many times the magnet passes the probe. Each pass equals one wheel rotation. You input your wheel's circumference, and the computer does the math:

Number of rotations x Wheel circumference = Total distance

That's it!

During setup, you'll tell the computer if you want your results in kilometers or miles. It'll also calculate the total activity duration, average speed, and max speed in addition to the total distance.

What bike computer to use?

Good news: Almost any bike computer will do the job. We run an open-door hedgehog rescue and small breeding program, so we often have lots of hedgehogs under our care. And being nerds, we often track the activity of several hedgehogs at a time. So we prefer simple, budget-friendly models. The included magnets are intended to attach to bicycle wheel spokes, so you may need to use a different magnet.

You can support us by purchasing one of our wheel loggers, which includes an upgraded magnet + adhesive that easily attaches to a wheel. Shop Link: Wheel Logger Kit

Most bike computers work very similarly, so this guide should help no matter which one you choose.

How to set up your wheel logger

If you get a wheel logger from us, we include easy printed instructions to follow. Below is a more detailed breakdown of each step. 

1. Calculate wheel circumference

1. Measure the diameter of the running surface:
• Use millimeters if possible. If using inches, convert to millimeters.
• For straight wheels, measure the outer edge.
• For tapered wheels, try to measure across the middle where your hedgehog runs.
• 
2. Calculate the circumference:
• Use this formula: Circumference = Diameter × π
• (you can simplify π to 3.14)
3. Write down the circumference for later programming.
4. See the table below for a list of circumferences of common hedgehog wheels.

Quick tip: If math isn't your thing, plenty of online calculators can do this for you. Just search for "circle circumference calculator" and plug in your wheel's diameter. Make sure you are using millimeters.

Reference Table for Common Wheels

2. Set up the computer

a. Pull the battery protector tab, or remove and replace the battery to enter setup mode.

• • Right button: changes the value
  • Left button: confirms and moves to next.
  • Button functions may vary between models. Check your manual if unsure. If at any point you hit the wrong button, just take the battery out for a moment to reinitiate the programming mode on startup. 

b. Input the circumference you calculated earlier.

c. Select miles or kilometers.

d. Set maintenance reminder (irrelevant but our model makes you pick, to my knowledge this doesn’t make any noise or really do anything)

e. Set time (optional, setting the current time in 12H or 24H format)

All done! It’ll now display the current “trip” results.

3. Attach computer mount

Use the included zip ties to attach the computer mount wherever is convenient for you on the stand. Just make sure it doesn’t interfere with the wheel’s ability to spin, and that you have space to slide the computer out of the mount bracket when needed.

Careful when you cut the excess zip tie - some of these aren't great quality and they will pop undone if cut too short.

4. Choose magnet placement to test

The magnet needs to pass very close by the sensor in order for it to register the wheel’s rotation. 

We use a piece of Frog Tape (our favorite masking tape) to test out a magnet placement on the back of the wheel while confirming that the sensor location is close enough.

5. Attach sensor, then test

Attach the sensor to the stand where the magnet will pass, using the provided zip ties. 

Make sure the computer is snapped into the mount. Then, spin the wheel to make sure it registers the magnet passing the sensor. 

The computer should detect the wheel is in motion. If not, move the sensor or magnet closer together.

If the sensor is too far away from the magnet, you can sandwich a scrap piece of foam, folded cardboard, etc. between the stand and sensor so that it's closer to the magnet.

6. Attach magnet and reset

When you’re happy with the placement of both, officially stick the magnet in place by peeling the paper from the adhesive, and tighten the zip ties for the sensor. If you're using the magnet included with the bike computer, you may need to get creative with a way to attach it securely to the wheel. Waterproof tape, nontoxic cement/epoxy, or silicone are all options.

Use an additional zip tie if desired to secure the excess coiled wire between the computer and the sensor. 

Press and hold the right button for 3 seconds to reset the computer, then you’re ready to go!

How to check the current results

• Depending on the type of cage you use, it might be easiest to pull out the entire wheel to view the computer screen, or take it off of the mount.
  
• On the model we use, 
  • The left button cycles through:
    • Dst (Distance, in km or miles, since last reset)
    • Mxs (Max Speed since last reset)
    • Avs (Average Speed since last reset)
    • Tm (Time in motion since last reset)
  • Clicking and holding the right button resets for the next night.

Note on accuracy:

• Max Speed can occasionally be inaccurate for pet exercise wheels.
• Why? When pets get off their wheels, the wheels may sway back and forth. If the magnet is right next to the sensor, the computer will read these small movements as full rotations.
• Average Speed can be slightly affected, but most hedgies run enough each night that the average speed calculation is pretty reliable.

We made a PDF Hedgehog Activity Log template that you can download and print if you'd like an easy chart to use!

How to reset for the next night

• On our model, click and hold the right button for 3 seconds. Check the included instructions if you're using a different model. 
• You don't have to reset every night. Maybe you check the results weekly, or whenever you wash their wheel.

Interpreting your results

• Tracking your hedgehog's activity over time is a really cool way to get insights into their health and fitness. You can determine if they tend to run the same amount every night, or are more active some nights than others. Does their exercise duration change depending on if they spent time exploring out of their enclosure with you during the day?
• If the computer indicates that your hedgehog was less active than they normally are, it might be time to double check their nails, their weight, and their skin health. 
• Decreased activity that goes on for more than a couple of days may warrant a vet visit.

Are you a nerd like us? We'd love to see your hedgehog's activity logs!

Troubleshooting and FAQs

What about when you're washing the wheel?
It's waterproof/water resistant, but take the computer off the mount so it doesn't track cleaning as running - or reset after cleaning.

What if nothing logged, but my hedgie made a mess and definitely ran last night?
If the computer ever fails to record, there are two likely culprits. Either the computer did not "snap" into the mount, or the sensor and magnet are not getting close enough on rotation. Make sure sensor is picking up the magnet as it passes -  you might need to move the sensor closer to the magnet.

What about the battery?
Batteries tend to last a long time in bike computers, often years. But you will eventually need to replace it. Our model uses an LR1130 button cell battery. They are a common size that you can find stocked in stores, but we also plan to offer replacements from us [Replacement Wheel Logger Battery] for your convenience if you don't want to buy multiple. They often come in packs of 6-10 of them, which would expire long before you got through them!