Other · Peromyscus and voles
Mouse
Also called Mousing, Night fishing.
Short answer
Mice and voles swim across rivers at night and fall in from banks, and the largest brown trout in a river will take one off the surface in the dark. Mousing is a night fishery, it catches very few fish, and the fish it catches are the ones nothing else will reach.
What a mouse is
Mousing is the most extreme form of the same logic that drives streamer fishing: the biggest trout in a river feed at night, on the largest prey available, in the places they feel safe. Mice and voles genuinely do swim across rivers and fall off undercut banks, and a big brown that will not show itself in daylight will take one with a noise that anglers remember for years. It is a specialist pursuit with a low hit rate. In Michigan it is a tradition on the Au Sable and the Manistee; in Alaska it is a standard tactic for Bristol Bay rainbows in high summer.
- Hook size
- Hook sizes 2 to 6, tied on deer hair or foam
- Colour
- Natural brown, grey and black. Colour matters far less than silhouette and wake.
The stages trout eat
- Swimming mouse
- The target. Fished across and down on a tight line, waking across the surface.
- Struggling mouse
- A pause or a twitch mid-swing imitates one in trouble, and often draws the take.
When does the mouse hatch?
| When | What is happening |
|---|---|
| June – August | The season. Warm nights, low light and active fish. Moonless nights are usually better. |
| Full dark | Not dusk. The best fishing often starts an hour after you can no longer see your fly. |
| Daylight | Occasionally works in Alaska and on heavily wooded streams, but it is a night technique. |
Emergence dates move with latitude, altitude and the weather of a given year. Treat these windows as a shape, not a diary, and check a local report before you travel.
Where it matters
Michigan's Au Sable and Manistee are the historic home of it. Alaska's Bristol Bay rivers in summer, Montana's larger rivers at night, and any river with a population of big nocturnal browns.
Fly fishing in Michigan Fly fishing in Alaska Fly fishing in Montana Fly fishing in Maine Fly fishing in Wisconsin
How to fish it
Cast across and slightly down, and swim the fly back with a steady tension so it leaves a wake. Do not strike at the sound — wait until you feel weight, which is the hardest discipline in fly fishing. Walk the water in daylight first so you know where you are standing. Use heavy tippet, 0X or 1X, and expect to catch nothing on most nights.
- Do not strike at the splash. Wait for weight.
- Scout the run in daylight. You will be wading it blind.
- A moonless night beats a bright one, and most nights you will catch nothing.
Flies that imitate it
Each of these is a card in the deck, and each has a full page in Our Fly-brary.
Keep reading
- Dry fly vs nymph — which stage to fish, and when
- Why trout refuse your fly — usually the wrong stage, not the wrong pattern
- Best time of day to fly fish — the daily logic behind the table above
- Our Fly-brary — every fly in the deck, explained