First you need to cut off the bottom and handle of the milk bottles.
Next place the sponge in the bottom cut off and trim it so it fits.
Then tape the middle parts of the milk bottles to each other and cover in the black pole stein plastic.
Now put the food colouring and peanut butter on the sponge.
Next cut off a bit of cardboard to fit on the bottom and place the paper (cut in half) on the cardboard.
Lastly put the sponge in the trap and place it in your backyard.
Here is a diagram of the rat tracker.