can they be raised as pets?
Yes, even though this trend is not very popular.
Mallard
While the keeping of domestic breeds is more popular, pure-bred mallards are sometimes kept for eggs and meat, although they may require wing clipping to restrict flying, or training to navigate and fly home.
when does a male mallards head turn green During the final period of maturity leading up to adulthood (6–10 months of age). what kind creatures are they? A dabbling duck . what are their food habits? Their diet consists mostly of gastropods, invertebrates (including beetles, flies, lepidopterans, dragonflies, and caddisflies), crustaceans, worms, many varieties of seeds and plant matter, and roots and tubers.
wiki:11694088
Mallard [SEP] Domestication
As the domestic duck and the mallard are the same species as each other, It is common for mallards to mate with domestic ducks and produce hybrid offspring that are fully fertile. Because of this, mallards have been found to be contaminated with the genes of the domestic duck. While the keeping of domestic breeds is more popular, pure-bred mallards are sometimes kept for eggs and meat, although they may require wing clipping to restrict flying, or training to navigate and fly home.