Reportedly, ants are the most numerous of all insects. They have only one or two queens per colony. When new queens are born, they have to leave and start their own colony. At this stage they are winged, and they fly to new territories.
Since ants are so numerous, ant "hatches" are of major importance to the angler in nearly every environment that contains insectivore fish. The carpenter ants are most notable because of their large size, but are only one of many ant migrations that happen in the region. Next time you are fishing a desert stream, stop and examine how many kinds of ants inhabit the barren landscape. There are a multitude of sizes and colors. Most seem to forage around water. Some do fall in. Trout and panfish love ants. Foraging ants are always wingless. But, remember that each species probably has a queen exodus sometime during the year.
On the west side of the Cascades, "terrestrial-insect-fall" is a very important food source for native trout in mountain streams. The first big terrestrial-insect-fall is the queen carpenter ant exodus. Carpenter ants are the largest ant species in our region and prolific in mature conifer forests. They produce some of the most important hatches of the season on our local lakes and streams.
Hatches happen when the air temperature climbs above 85-degrees for the first time during the spring or summer season. At the 1,200' elevation near our store, the air is filled with big glossy black queens during the first hot days of the season. While the hatch timing can vary drastically with elevation or climatic changes, expect to see carpenter ant queen flights from April up through August in Frog Lake and Timothy Lake, which are about 3,500' in elevation.
Ants are clumsy fliers and don’t stay on the surface of the water for very long before they drown and sink. Fishing an ant pattern as a wet fly can be very productive any time the weather is warm, but especially during or just after a queen migration.
Locally, ants vary greatly in size from approximately 3/32” to ¾”. Most ant bodies are very dark - brown, gray, or black. Some ants are reddish brown, while others have black and red parts. Most of the major queen flights that I have observed have been dark brown to black colored and had brown wings. The average sizes of flies to match the different species are #16, #14, #12, and #10.
My two best ant hatches were an early morning flight of small dark brown ants along a famous tanky steelhead run on the lower Deschutes. Trout were rising in a large area right in front of camp. My clients were all below camp chasing steelhead, which left their guide all by himself in the camp water to solve the hatch with a five weight. The flight lasted a long time and the exact hatching matching fly were in my boat, and I had a dozen of them.
The other time was on the Kilches River during a fall cutthroat trip. A large, shaded pool held several dozen fish, but we were unable to get any of them to bite. In frustration, I finally waded upstream searching for other action. After a couple of hundred yards of shallow barren riffles, I came to a deeper pool on a corner where the river ran under a small log jam. In the center of that jam a large, weathered and rotting log was covered with winged ants - literally thousands of them - just above the waterline. Then I noticed that there were trout feeding on them. Once again I had the exact matching fly. The cutthroats paid dearly for their greed. All were release unharmed.
Real ants are very hard to see on the water, even the winged ones. Some ant dry flies are dressed with white or colored Antron wing to make them easier to see in adverse light conditions. Antron is easily colored with a water proof felt marker to help give you an even greater edge. We suggest you carry dark gray and brown markers. You may also easily refashion or remove the wings with your leader clipper.
Be sure to carry a few winged and wingless ant patterns to cover a variety of situations. Floating ant dry flies can be effective searching patterns for everything from blue gills to sea run cutthroats. Winged ant dry flies are essential to have in all sizes. Wherever ant queens are migrating around water, there are fish eating them, making a carpenter ant fly pattern an especially good one to have on hand when fishing locally.