Humans are undoubtedly altering the natural environment. But how wild animals respond to these changes is complex and unclear. Scientists have now discovered significant differences in how the brain works in two distinct personality types: those who act fearless and those who seem afraid of new things. Being fearless can help wildlife, specifically birds, find new food sources, explore new nesting areas and help them adapt to changes in their environment; but being afraid can also help protect them from dangerous novel things in their environment such as cars.