Traps seen in use during our projects of yesteryear (AT Project, Kingston Project) were intended for use at cave and smaller mine entrances during emergence and swarming seasons. These PVC devices have been used routinely with excellent success in the NE US for well over 15 years. Though seemingly inexpensive to build, the non-collapsible frames, bulky catch boxes, time consuming assembly, UV deterioration, and overall size limits pose significant drawbacks.

Over 4' wide PVC just doesn't cut it anymore. Essentially our trap construction project came about when we needed a number of larger devices for our summer projects, but we were not satisfied with the design, availability, and price of the few other commercial offerings. As a result we have developed several sizes of aluminum and stainless traps for our own use. After several seasons of refinements and incorporating suggestions from other working field biologists, these devices represent the top shelf bat traps of today. These traps incorporate a number of refinements and fresh ideas not seen in any other design to date.

Two sizes have proven to be most useful over the years. A medium 3' (0.9m) "cave catcher" model (3' w X 2'-3.5' h. maximum catch area: 10.5 square feet (0.98 square meters) weight: 15 lbs.) is useful at smaller cave, mine, and structure entrances. A large 6' (1.8m) "forest strainer" model (6'x X 5'-7.5' h. maximum catch area: 45 square feet (4.2 square meters) weight: 28 lbs. with legs) is more appropriate for large entrances, small diameter pit entrances, forest trails, and narrow stream corridors.

Some requested a Three Bank trap, for use on those pesky mega bats found outside the US. We wrestled with the idea and decided to elegantly convert our existing trap systems into a Quad-Bank Harp Trap for unmatched versatility. Two traps are combined into one unit using an Expansion Joint and Super Moose Ears. This type of trap may be used to determine flight directions of bats at hibernaculm entrances, for example. You may also just use the Expansion Joint alone to connect any two traps side-by-side at any angle to straddle muck or cover two sides of a trail intersection at once. Connecting two 6' traps yields a maximum catch area of 90 square feet (8.4 square meters). (Note: Expansion Joints will not work with new G5 traps, only previous models.)

Trap anatomy
Composed of aluminum with stainless hardware, there is nothing to rust. You can anodize your trap flat black locally (or paint) for perhaps a big increase in stealthiness. Assembly is fast with cotter less hitch pins on pull rings, so no tools are required. Two extra pins are installed on board, and in practice not all of the hitch pins are required to normally use the trap, so the loss of a few won't ruin your trap session.

The telescoping Uprights feature two lock knobs on each post for extra tension security. Telescoping legs are built into the columns and are never removed. Picking up the trap never leaves your legs behind, and legs are adjustable at any increment.

The lines are held tight on the top bars with individual stainless hardware rubber lined to avoid line wear at this joint. No knots are required anywhere here. Simply loosen the screw, feed in the line and tighten. We wanted the option to use high strength black spectra lines which are impossible to use on comparative systems due to the low stretch. Individual tensioning solves that.

Adjusting a line in the dark is easy with a common "phillips" style screwdriver. Since the entire trap is connected it may be hung from the top.

It's in the Bag
The catch bag is a deceptively difficult engineering problem, as the bats are quite crafty escape artists. Our bag is made from heavy duty clear vinyl, ungrippable and easily cleaned. The bag's sidewalls are raised above the bottom trap line bars. This should make it more difficult for bats to escape out the sides if they land on the Lower Line Bars. The Baffle Bar holds the all important plastic baffle, thwarting flight within the bag. A narrow removable lining (seen along the bottom left on the inside of the bag) is a roost platform. This is a layer of canvas with a vinyl overlay where the bats can rest and await their fate comfortably instead of flailing about. It is also totally removable (Velcro) and washable.

Bungee cords adds tension along the front and back of the bag, decreasing the size of the entrance and restricting flight further. The bottom of the bag contains grommet drainholes to help avoid unwanted swims.

Actual products differ slightly from photos presented here (i.e., no green catch bags anymore, only clear.)

Ready for even more trap viewing?
Download the e-drawing of an earlier version of our harp trap-- it rotates, it zooms, and it spins. Download, double-click it, and press the "play" button. The file contains the 3-D viewer and the drawing combined. Windows or Mac running Virtual PC.

Not sure what is a harp trap?
Be aware that harp traps are fairly complex devices with numerous machined parts. Additionally, there is a right way to use them and many, many wrong ways. Consequences of misuse or ignorance range from setup frustration to capturing nothing to accidental bat deaths. This device is not intended for pest control applications and may be against state laws if used in that respect. Expect to spend several hours familiarizing yourself with the trap's versatility before on site use. Please review the Support page or general discussions if you are unsure if this is the right sampling device for your project. We stand behind the craftsmanship and usage of the device as advertised. We will repair or replace any defective part and may refund the purchase price of the device (except shipping costs) should the buyer decide this was not the tool for their particular job.

3' Cave Catcher: $650.00+ $25 flat shipping in USA. Includes Leg Mate, travel bag, & line. Total weight: 11 lbs.

6' Forest Strainer: $950.00 +$40 flat shipping in USA. Includes Leg Mate, travel bag, & line. Total weight: 28 lbs.

Expansion Kit: $125.00+shipping. Includes two Expansion Joints and will join any two traps together. Used with 6' traps, this will create a "wall" of trap 12' across with no center support needed. Also includes two Super Moose Ears enabling any two identical traps to merge into one "quad bank" trap.

Catch Bag: $65.00+shipping. Newest clear model with integrated bat roost. Attacked by owls and need a second? Specify 3' or 6' model when ordering.