But big pike and little pike might as well be two entirely different species. Big pike crave cooler water, for example. By summer, they’ve abandoned the shallow weed flats you’ve been fishing since spring and followed the thermocline into open water. Now that October is upon us, however, big fish are moving shallow again. Cooling waters are the main reason, but big pike are also following favored forage—fall-spawning ciscoes and whitefish.