Traparium: Making Traps Pet-Safe

About: Lifelong interest in making and learning new things.

My coinage of the word "Traparium" is intended to convey the idea of a container that encloses a trap of some kind, in this case a mouse trap. A traparium itself is not a trap but it houses a trap for a variety of reasons.

Plastic pipe fittings made from PVC or ABS plastic makes an excellent traparium because plastic pipe fittings are relatively cheap, strong and the abundant sizes and shapes allows for specific customization.

This tutorial will show how easy it is to build a traparium using simple hand tools.

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Step 1: Why Make a Traparium?

Why do I need a traparium?

I have a most able Mouser and excellent Instructables Assistant who keeps my home mouse-free. There are times, however, usually when the weather cools, when a field mouse finds a way inside and locates a good stronghold that my cat can't breach.

Eventually the mouse, emboldened by his or her good fortune, will venture a bit too far from the stronghold and be caught by my trusty assistant but that may take time and I want more immediate relief. My dilemma is: How can I set a mousetrap and still protect my cat and my toes from accidentally setting off the trap?

The traparium elegantly solves this problem by allowing a mousetrap to be placed inside the traparium thus protecting against accidental encounters by myself or my cat. A mouse can enter but the design is such that the mousetrap inside the traparium is beyond the reach of my cat.

Step 2: Materials and Tools

Plastic pipe fittings are strong and nonporous making them excellent materials for a traparium that will locally contain messes and can easily be washed and disinfected as needed.

This traparium is made from 3 inch (76 mm) plastic pipe fittings all readily available from hardware stores.

Materials List:

1 - snap in drain
1 - clean out adapter fitting
1 - test tee fitting
1 - 90 degree street elbow
1 - flush bushing [3 x 1.5 inches (76 x 38 mm)]
1 - bolt .25 inches (6 mm) in diameter and 1 inch (25 mm) in length
2 - washers to fit the bolt
2 - nuts to fit the bolt

Solid brass or stainless steel are good materials to consider when selecting the bolt, washers and nuts as they can be washed along with the traparium and won't rust.

Tools List:


Step 3: Assembling the Traparium

In Photo 1 I have laid out the arrangement of the plastic pipe fittings in a kind of exploded view of the traparium.

Start with the "test tee" fitting (Photo 2) and insert the "clean out adapter" fitting into one end of the "test tee" fitting until it fits snuggly as seen in Photo 3. This will be the service entrance where the mousetrap will be inserted and retrieved from the traparium. The threaded cap is the door (Photo 4).

Insert the "90 degree street elbow" into the other end of the "test tee" until it fits snuggly as seen in Photos 5 & 6. This is the mouse entrance into the traparium. The "90 degree street elbow" should be inserted so that it will lie flat on the floor in order to keep the traparium upright in its proper position. It also creates an elongated, curved entrance that is longer than a cat's arm, so the mousetrap, which is placed in the "test tee" section, is beyond reach.

Next insert the "flush bushing" into the other end of the "90 degree street elbow" as seen in Photos 7 & 8. This reduces the opening to help prevent a cat from trying to reach into the traparium with its paws. The opening is still plenty big enough for a mouse to enter (Photo 9).

The plastic pipe fittings that make up the traparium could be cemented together if desired but I prefer not to cement the fittings because I want to be able to disassemble the traparium for easier cleanup as needed.

Step 4: Assembling the Vent Viewer

The last step is to assemble the vent viewer by attaching the bolt to the center hole of the "snap in drain" by placing one washer and one nut on the upper and lower surfaces of the "snap in drain" as seen in Photos 1 & 2. Use a screwdriver and wrench to tighten the bolt and nuts.

Finally, place the vent viewer into the "test tee" as seen in Photo 3.

The vent viewer allows one to view the mousetrap inside the traparium to check on the condition of the mousetrap. Some mice are extra clever and can remove bait without setting off the trap. It is simple to lift off the vent viewer, using the bolt as a handle, and sprinkle some bird seed or bread crumbs on the mousetrap to replenish the bait.

The vent viewer also allows fresh air to enter the traparium so the mouse may sense that the traparium has another entrance/escape route and thus may be more willing to enter the traparium's one and only mouse entrance.

Step 5: Using the Traparium

To use the traparium, unscrew the door to the service entrance and carefully slide in a baited mousetrap until the trap is below the vent viewer. Then screw the door back in place to close the service entrance (Photos 1 - 3).

Set the traparium at the desired location and monitor as needed.

To better monitor if mice are entering the traparium, add a spoonful of baking soda into the traparium via the entrance and sprinkle inside (Photos 4 & 5).

Gently shake the traparium from side to side to better smooth and level the baking soda on the floor of the entrance. This step should be done prior to inserting a baited mousetrap otherwise the shaking motion will likely set off the mousetrap.

The baking soda, initially smooth and level, will show signs of tracks if mice are passing in and out. The baking soda will also act as a deodorizer if droppings or urine are left. Once the mouse is caught, everything can be emptied out of the traparium via the service entrance and the traparium can be washed and disinfected.

After washing, allow the traparium to air dry. Once dry the traparium will be ready for future use.

Step 6: Final Thoughts

The traparium is an effective way to protect paws and toes from unintentional contact with a baited mousetrap. It is a great way to keep the home free from mice when pets freely roam the house.

The traparium is practically indestructable but if a fitting should ever become lost or damaged it can easily be replaced, but only if the fittings were not cemented together.

The relatively cheap plastic pipe fittings allow one to construct as many traparia as may be needed to keep mice out of the home and garage and to keep peace of mind knowing that pets are protected from the traps.

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    6 Discussions


    1 year ago

    possible to catch mice without killing them with this device like the view to drop mice through and plug all other openings

    1 reply

    Reply 1 year ago

    With all of the varied plastic pipe fittings, it is easy to modify this design as desired.

    Birdz of a Feather

    1 year ago

    Great idea; we've been using something very similar for years and it works great, but I think you've built an even better mousetrap. We'll have to try it out :)

    1 reply

    1 year ago

    What a useful and intelligent idea. Authorities have removed the rat's predators like the owls, garter snakes, etc. and now we have a rat population explosion. (Because some people were afraid of owls and non-poisonous snakes and called animal control & being public servants they had to remove them - now we have worse - we have fat rats that bite people). The woods got flooded and we are overwhelmed with rats. They eat wood, plastic, chew holes through trash cans, they chew electric wires, they chew through floors, eat garden plants & bulbs and they get into homes and they bite people while they are sleeping. They are cannibals by nature. It looks like this invention of yours, might prevent injury from checking rat traps. I am speaking to my husband about building a slightly larger version because our rats here are over-fed. People leave food out for the birds here but the rats eat it, & they made it easy for the rats to get into their garbage. (I can't understand why people would be afraid of owls when rats can bite them in their sleep and eat faces and feet while they are sleeping. Garter snakes aren't interested in eating us, they eat rats instead and now they are gone. When people poison a rat and they burrow into the liner of your house while they are dying and die inside a floor or wall where you can't find them and then stink up the place for months.) I sure hope this thing works! We need it.

    1 reply

    Reply 1 year ago

    A larger size of plastic pipe fittings would be needed for a rat trap to fit inside. Hope it helps.