<Tr> <Td_colspan="2"> Problems playing this file? See media help . </Td> </Tr> <P> Like many woodpeckers, its flight is undulating . The repeated cycle of a quick succession of flaps followed by a pause creates an effect comparable to a rollercoaster . </P> <P> According to the Audubon field guide, "flickers are the only woodpeckers that frequently feed on the ground", probing with their beak, also sometimes catching insects in flight . Although they eat fruits, berries, seeds, and nuts, their primary food is insects . Ants alone can make up 45% of their diet . Other invertebrates eaten include flies, butterflies, moths, beetles, and snails . Flickers also eat berries and seeds, especially in winter, including poison oak and poison ivy, dogwood, sumac, wild cherry, grape, bayberries, hackberries, and elderberries, as well as sunflower and thistle seeds . Flickers often break into underground ant colonies to get at the nutritious larvae there, hammering at the soil the way other woodpeckers drill into wood . They have been observed breaking up cow dung to eat insects living within . Their tongues can dart out 50 mm (2.0 in) beyond the end of the bill to catch prey . The flicker is a natural predator of the European corn borer, a moth that costs the US agriculture industry more than $1 billion annually in crop losses and population control . As well as eating ants, flickers exhibit a behavior known as anting, in which they use the formic acid from the ants to assist in preening, as it is useful in keeping them free of parasites . </P> <P> Flickers may be observed in open habitats near trees, including woodlands, edges, yards, and parks . In the western United States, one can find them in mountain forests all the way up to tree line . Northern flickers generally nest in holes in trees like other woodpeckers . Occasionally, they have been found nesting in old, earthen burrows vacated by belted kingfishers or bank swallows . Both sexes help with nest excavation . The entrance hole is about 7.6 cm (3.0 in) in diameter, and the cavity is 33--41 cm (13--16 in) deep . The cavity widens at bottom to make room for eggs and the incubating adult . Inside, the cavity is bare except for a bed of wood chips for the eggs and chicks to rest on . Once nestlings are about 17 days old, they begin clinging to the cavity wall rather than lying on the floor . </P>

Bird with red stripe on back of head