How to Humanely Kill Mice

Mice are a staple in the diet of many reptiles including snakes and large species of lizards. Mice can be fed either live or killed, although it is generally considered safer to your reptile to feed killed mice to avoid injury. You can purchase feeder-quality dead mice from pet stores, although it can be expensive. Humanely killing your own mice at home can be done with just a few items and will make feeding your reptiles much more affordable.

Things You'll Need

  • Empty gallon jar with lid
  • Knife
  • 1" diameter plastic tube, 3 feet long
  • Shredded newspaper
  • White vinegar
  • 16 ounce measuring cup
  • 3 tablespoons baking soda
  • Gallon size ziplock bag
  • Duct tape
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Instructions

    • 1

      Cut a small hole in the jar lid with your knife, just large enough for your plastic tube to fit into. Slip the tube in the hole and seal the edge of the hole tightly with duct tape. This tube will be used to carry the carbon monoxide gas into the jar and the seal must be tight to effectively kill the mice.

    • 2

      Add a layer of shredded newspaper to the bottom of your jar. The newspaper helps provide a soft bedding for the mice and helps cushion then and prevent injuries in case they try to escape from the jar. Place your mice inside the jar and screw the lid on tightly, wrapping around the edge with tape to make an airtight seal.

    • 3

      Place 3 tablespoons of baking soda in the bottom of a plastic bag, placing the measuring cup on top of the baking soda in the bag. Fill the cup with 16 ounces of white vinegar and place the tube just inside the top of the plastic bag. Slide the zipper closed on top of the bag, sealing the opening with a piece of duct tape.

    • 4

      Hold the handle of the cup through the plastic bag and slowly pour the vinegar from the cup into the bottom of the bag. The vinegar combines with the baking soda and releases carbon dioxide that will travel through the tubing and into the jar, slowly depressing the nervous systems of the mice. They will slip into unconsciousness and eventually death as the gas replaces the oxygen in their bloodstream.

    • 5

      Leave the jar closed for at least thirty minutes to make sure the mice have passed away. Remove the tape and unscrew the lid, pulling each mouse out and checking for signs of life. If there is no movement or breathing, you can either feed the mouse to your reptile or freeze for later use. If any of the mice are still conscious, reseal the jar and repeat the gassing process.