How to Make & Use an underwater Light Trap
How to Make and Use an Underwater Light Trap
Materials Needed:
- a length of stove pipe about 15 inches long
- a 1 inch board as wide as the diameter of the
stove pipe
- a square foot of window screen
- a flashlight
- a screw-cap jar big enough to hold the flashlight
- a weight
- three small screws
- an eye hook
How to Make:
- Make the funnel for the trap by cutting out a 1-
foot diameter circle from the piece of window
screen and then cut the circle in half.
- Next, fold one of the half circles in half and sew
its two straight edges together. You now have a
flattened cone.
- Open the cone and cut off its tip to make a
funnel.
- Put the funnel into one end of the stove pipe,
and fold the lip of the funnel back over the
stove pipe. Use wire, string or water-proof tape
to hold the funnel in place on the stove pipe.
- To close the other end of the stove pipe, make
a snug plug from the 1-inch thick piece of
board. Fasten the jar lid to the center of the
plug using 1-inch screws. The screws must be
screwed in snugly so the jar will not leak.
- Then drill one or two 1-inch holes in the plug
and cover them with screen.
- On the opposite face of the wooden plug,
screw in an eye screw. Use three screws to
hold the plug in the stove pipe as shown in the
drawing, or else the plug may pull out when
you retrieve the trap from the water.

How to Use:
- When you want to use the trap, remove the
wooden plug and put in the weight and the
turned-on flashlight in the jar.
- Replace the wooden plug and attach a long
string to the eye-hook.
- Lower the trap gently into a pond or stream,
and tie the string to some solid object on the
shore.
- After leaving the trap in the water for several
hours, retrieve it, using the string to find it. Lift
the trap slowly from the water, funnel end first,
letting the water drain out of the trap through
the holes in the wooden plug.
- Remove the wooden plug to get the insects out
of the trap. Do this over a large shallow cake
pan to keep insects from crawling away. The
trap may also have small fish in it which should
be returned to the pond or stream.