My cat is about 8 month old and i have just recently neutured him. Sometimes he will stand behind the window and make meow noises like as if hes whining.(mostly at nights).and there are cats by my area that just seem to come by my door ...and sometimes i leave the metal door open where u can see everything outside ..the cat will just stand outside and my cat will see him and run and they just stare at each other so i just end up closing the door...i dont know..is this whining normal? should i let them stare at eachother ?