As a general rule, fish bite bait taken from their native water. Look in the water near the shores for crabs, fish eggs, and minnows and on the bank for worms and insects. If you catch a fish, inspect its stomach to see what it has been eating; then try to duplicate this food. Use its intestines and eyes for bait if other sources are unproductive.
– from the 1969 Dept. of the Army Field Manual Survival Evasion and Escape