A German shepherd named Moose the Dog on TikTok has two distinct barkings, one when he plays with his dad and another when he believes he sees an intruder as an intruder. The video shows Moose's shift from playing to protecting, while the second half shows him full-on barking in a defiant stance when he sees what he thinks is an intruder, which he immediately reacts with delight. The dog's bark can vary by pitch, frequency, and length depending on what it's trying to convey, ranging from deep territorial warnings to playfully shrill yelps. If a dog is feeling anxious or feeling lonely, a mid-pitched, deliberate bark with timed pauses in between indicates its need for attention is what they use to convey.