Birds generally avoid unusual things and prefer green and blue objects  But when researchers injected baby mallard ducks at 4, 9 and 14 weeks with sheep red blood cells to simulate a parasitic infection, but when researchers injected baby mallard ducks at 4, 9 and 14 weeks with sheep red blood cells to simulate a parasitic infection  The birds began to explore new things in their environment and approached the small orange toys-They usually keep away from the color because it seems to be associated with poisonous food  The researchers speculate that these so-called personality changes will help adult individuals explore larger areas, and find more food
Adult mallard ducks exploring a larger area means facing more dangers.
 These things in turn, make up for the energy they lose in fighting infectious diseases