Answer:
Weird supernatural things that have been happening. Unnatural occurrences. Links to rest of play because nature is reflecting what is going on in the play. Unnatural happenings. Strange things that have been happening in the past week involving nature. An owl killed a falcon (unnatural?). Duncan's horses have been misbehaving and one horse ate the other. Donalbain says this to Malcolm. It means that he fears they will too be killed in an attempt for someone to inherit the throne. They decide to flee the country for safety. Malcolm goes to England. Donalbain goes to Ireland.