Bob Kwalwasser of Connoquenessing Township shows two of the more than 4,000 mouse and rat traps he has collected. Kwalwasser has been collecting the traps since the 1950s and has them displayed in basement cases. Even with all the traps he's got, Kwalwasser says there are about a dozen that he would like to add to his holdings, but has been unable to find.

"There are many different ways to catch a mouse or rat," Bob Kwalwasser of Connoquenessing Township said.

And he should know.

The longtime collector has amassed more than 4,000 mouse and rat traps since his interest formed in the 1950s.

Displayed in cases throughout his basement, the traps represent all continents and constructions from primitive times to the present. The traps are made from wood, wicker, metal or glass to accomplish their task by various means.

In some, carefully crafted doors slam down when a mouse chews through a bait-coated string.

In others, electric currents do double-duty: A jolt kills the mouse while throwing it aside to clear the way for other intruders.

"They put a wet napkin in front to be sure the mouse would have good contact," Kwalwasser said, showing a group of electricutors designed to plug into outlets formerly found in baseboards.

Not without humor, a small statue of the Pied Piper stands near two more clever traps.

One claw-style metal one is fashioned into a face in which the eyes roll as the "mouth" snaps shut. Another, made in the mid- to late-1800s to look like a car, will motor across the floor when an entrapped mouse powers it with a treadmill.

"Our forefathers were pretty clever — especially without the tools we have today," Kwalwasser said. "Some are gorgeous in their construction and quite practical."

Although the constructions prompted him to start buying traps more than 50 years ago, Kwalwasser's collection doubled about four years ago when he purchased a collection from Germany. That collection belonged to the late Reinhard Hellwig, who co-authored a book on traps and whose collection was featured in the 1998-99 edition of the "Guinness Book of Records."

"I believe I am the largest," Kwalwasser said of his collection's size.

"I would say yes," agreed Tom Parr, president of the North American Trap Collectors Association who traveled to Pennsylvania two months ago to appraise Kwalwasser's collection.

Although Parr describes the accumulation as noteworthy — having been featured on the History Channel's "Modern Marvels" show — he said trap collecting itself is not uncommon. The association has maintained more than 1,200 members for the last 10 years after forming in 1985.

"Our membership really consists of men and women, and their collection habits could be anything from mouse traps to bear traps, and everything in between," Parr said. "In the 1920s, trapping was quite the in thing. There were well over 100 trap manufacturers in the United States. With mouse and rat traps, there were so many makes and models. Everybody tried to build a better one."

Although the trap collection is Kwalwasser's most significant, his home is adorned with other treasures.Primitive copper cookware leads up to the great room's vaulted ceilings. Pocket pencil sharpeners occupy tables, while a group of antique whisks and egg beaters hang on a mobile from the ceiling.On the fireplace mantel are a collection of traveling ink wells collected by his late wife, whose love of tramp art — items sculpted from matches, tooth picks or Popsicle sticks — also is evident throughout the house.Washboards of every kind flank the basement stairs, while a shrine of roller skates, ice skates and snow shoes decorate a wall near the greenhouse door."We both were collectors," said Kwalwasser, whose outings have always included antique shows and fairs. "The hunt has a lot to do with the brains of people who are collectors."Kwalwasser also owned a salvage company in Pittsburgh before retiring some years ago. Some of the less marketable salvaged items also are featured throughout the house, having been made into chandeliers, table lamps and other useful things.With a long history of assessing value, whether working in salvage or buying antiques, Kwalwasser has witnessed some changes over time. Many stem from the Internet, since information posted there has changed people's perceptions about the scarcity of items.Some traps that once sold for $30 or $40 now are being sold for $5 or $10, he said. Additionally, truly scarce traps are now being made available to a wider audience, often increasing their price."The scarce ones bring top dollar," Kwalwasser said.Linda Kruger, head of the Iowa-based Collectors Information Bureau and editor of three publications, agreed."It's opened the marketplace up so broadly that we're finding out that some products that originally seemed to have a finite number are actually very available," she said. "(But) the Internet makes things available to us from all around the world, so in a lot of ways, that's been an asset to collectors."Kwalwasser said despite online availability, some traps remain absent from his collection."I know of probably a dozen or more I would like to have but don't have," he said, noting he has the original patents for a few, but doesn't know if they were ever manufactured.The challenge also remains to procure traps in prime condition. Most antique traps have been used, and more still were stored in basements and barns, compromised by the dampness."To find them in good shape with labels on them is tough," Kwalwasser said. "But there are some out there, so I keep looking."

Bob Kwalwasser walks by display cases containing some of his massive mouse and rat trap collection. Kwalwasser has amassed more than 4,000 traps since the 1950s, and four years ago, he purchased a collection from Germany, doubling his collection, which he believes is the largest in the world.