My dog is a little terrier mix of some sort, but she is surprisingly very mellow most of the time. She loves to cuddle all day, nap, and play with my other dog. We make sure she gets exercise, and she seems very content. At night, however, once we go to bed, if she hears something outside, she immediately starts barking at it, waking us up. She stops pretty quickly and goes back to sleep, but this is happening 5-6 times a night, and keeping everyone up. Any suggestions as to what I might do?