Caenis Madness!

We know how infuriating it can be when you want to enjoy a nice summer fishing and the Caenis hatch thwarts your efforts, leaving you muttering profanities under your breath at the infuriatingly tiny flies.
Caenis is a generic name for eight species of flies so similar they can be treated as one.

Matching the hatch when the Caenis is in abundance is tricky at the best of times as your fly is lost amongst the thousands of naturals there are on and in the water. The fish are feeding higher in the water than you would be used to so they have a more tunnel vision view and are much more likely not to see your fly at all!


More frequently found on large lochs and reservoirs than rivers but they can obviously be found on both. The life cycle can be found happening all at the same time, within minutes a Nymph begins to rise towards the surface and hatches into an adult dun where they will take to the skies and land on anything (or anyone) and shed their skin. Transforming into a Spinner, taking to the sky again to find a mate and the female will return to the water to lay eggs again for the next generation.
Photo curtesy of Allan Liddle, covered in Caenis flies.

Caenis Flies

Caenis Nymphs are tiny 3-5mm moss creepers which live amongst the vegetation on lake and river beds.

Dun flies are similar in size to the Nymphs and hatch in open water during th Summer months, typically in the morning or evening. Easily recognised (if you have good eye sight for that size) with their creamy-white wings, short bodies and three tails.

Spinners, a Trouts favourite of the three for dinner time.

Very similar in appearance to the Dun but with more translusent wings and much longer tails.
Image from Allan Liddle, his favourite Caenis Spinner fly against an adult Spinner.

How on earth do you fish when there is Caenis madness?!

  • Pick one target and stay focused on it. Watch it, get to know its habits, when it is most likely to strike. Aim your fly directly in front of the fish before it strikes, aiming your fly directly on the nose.
  • Be as close as possible to your target to ensure accuracy and fast casting and striking.
  • Stay in one place, noises from boats or wading will hinder your chances and the fish will simply move away.
  • Think about what the fish are feeding on and try something not exactly matching the hatch, try a variation, buzzers and small sedges work well sticking to roughly the same size as what’s hatching.
  • Set yourself up to intercept the frenzy without disturbing the water too much.
  • A dry Caenis imitation can be slowly twitched through the surface film to provoke aggressive bites when trout are pre-occupied with Caenis hatches.
  • If your target is too far for your casting range, or you are rushing your casts and getting infuriated then find a different spot if possible or a different shoal feeding on something else.
  • Once you have caught a fish, lead it away from the shoal so that they are not disturbed or frightened and swim away.
  • Look for shoals of feeding fish, keep a single target in mind, but if it swims away then simply pick another. Don’t go wading to catch it as all the fish will disappear and your trip with them.
  • Keep alert, Caenis madness is not limited to a specific time of day. When conditions are right you can encounter a feeding frenzy during light winds, calm conditions or secluded sheltered spots.

Keep trying, hang in there, you will master
Caenis Madness!

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