Aqua Flies Mr Hankey- Big trout like a big meal. Mouse patterns can be one of the most effective big trout flies. These patterns tend to be large and noisyto catch a trouts attention and can often entice big trout, who are reluctant to chase the typical offerings. Tied with buoyant materials, it is hard to sink these flies. Our mouse flies are rigged with either a size 2 or size 4 AquaTalon hook.