As the duckling grows older, more vegetable matter is eaten. Most mallards will have attempted to nest by early May. Renesting attempts, if nests are destroyed, will take place after this date and may extend well into July. A wide variety of nesting sites are used by mallards, although they seem to prefer fairly dry sites with rather tall vegetation. Some hens will nest in marshes on muskrat houses or other over-water nesting situations.
Islands also provide safe nesting sites for mallards.