nuddle

As a verb nuddle

is (uk|dialect) to walk quickly with the head bent forward.

As a noun noddle is

(uk|informal) the head; the part of the body of an animal or human which contains the brain, mouth and main sense organs.

As verbs the difference between nuddle and guddle

is that nuddle is (uk|dialect) to walk quickly with the head bent forward while guddle is to catch fish with the hands, especially by groping under stones or at the banks of a stream.

As verbs the difference between ruddle and nuddle

is that ruddle is to mark something with red ochre while nuddle is (uk|dialect) to walk quickly with the head bent forward.

As a noun ruddle

is a form of red ochre sometimes used to mark sheep or ruddle can be a riddle or sieve.