Once the water begins to warm up on your favorite pike lake the aggressive tendencies of northern pike will become intense! Pike feed on a lot of different things, but most of us fly fishermen use large streamer flies to emulate the resident forage fish. Often this is bluegill, suckers, young bass and perch...but in a lake that has a thick population of these toothy carnivores they will greatly decimate the forage fish populations. Sometimes this will get so bad that the local pike will eagerly turn to cannibalism! Some areas I have fished in the past there were no other species in the lake besides pike...they were eating their young just as fast as they were procreating! Guess it saves a ton of money on diapers...and groceries!
I have a fly in my pike box I call the Hammer Handle (the popular term for a young pike).