The Oil-Moat Insect Guard: Up the Leg, Out the Flange, Down Into the Oil

"The object of the present invention is to provide a simple and inexpensive insect-trap adapted to be readily applied to the posts of houses, the legs of a table, or the like, to prevent ants, mice, or rats and other vermin entering a house or house-safes or getting on a table or after suspended meat." "Ants or similar insects in attempting to ascend the leg or the post of a house will ascend the outer face of the tube 3 until they reach the horizontal flange 4, when they will pass to the sides of the casing 1 and descend into the annular space and drown in the oil or return. In either case the insect will be prevented passing up the leg farther than the horizontal flange."

Glue two dowels upright into holes drilled in two small boards: these are two table legs. Put a spoonful of sugar wetted with a little water on top of each. Take a tin can with its top removed. Drill a hole in the centre of its bottom that fits the dowel closely. Turn the can upside down, so its bottom is the guard's top, and slide it down one dowel to halfway. Hot-glue it all round the hole so nothing can pass. Cut a disk from the lid of a second can, about 1 cm smaller than the can, with a hole in its centre for the dowel. Slide it up inside the casing to halfway and glue it round the dowel: this is the flange. Cut a strip of tin 3 cm wide, bend it lengthways into an L, and hot-glue it inside the open rim to make a gutter. Drill a small hole in the top, pour cooking oil through it into the gutter, and seal the hole with tape. Set both posts on an ant trail outdoors. Count the ants on each sugar after one hour, and again the next day.

**Sterling Walter Conrad** of Hanford, California, filed US 460,429 on 8 January 1891; it is dated 29 September 1891. The patent names ants, mice and rats. This rung tests it on ants only. **Honest limits.** The guard only works while nothing else touches the leg or the casing. The oil needs cleaning and topping up. The notebook's sizes are examples. Your ant counts, on the guarded and the unguarded post, are the measurement.