Here is a cute idea I saw on line…(where else) if you use a pin, you can scratch a message into a banana… The neat part is that it get darker with time, so when you scratch your message in the morning, you can barely see it, but by the time the kids open up their lunches, it will have turned almost black.
All you need is a pin, a banana, and an idea…

Use the pin to scratch a message onto the banana….You don’t have to press too hard, just enough to scratch the surface…

Then pop it into a lunch bag, and wait!

Sam drew a picture on her banana…

Then, I tried a fancy one…

Update… Here is what it looked like a couple hours later!