Anyone with a dog knows that it's hard to leave them every day. They always want to come with you, and look so sad when they realise you're going out without them.
But are they really missing you, or do they just want to explore the outside world?
As the latest episode of BrainCraft explains, there's neuroscientific evidence to show that dogs really DO miss us - just like we'd always hoped.
BrainCraft's creator Vanessa describes a very cool recent study, where a scientist trains a dog to lay still in an MRI machine, so they could study its brain activity.
During the research, the team found that dogs really do understand what their owners are saying. But it also tested whether they miss us, by exposing the dog in the MRI machine to five different scents - its own, the scent of a familiar and unfamiliar dog, and a familiar and unfamiliar human.
Interestingly, when the dogs smelt a familiar human, the caudate nucleus of their brains lit up - a region associated with positive expectations and rewards.
Another study looked at how dogs behaved with people of varying levels of familiarity - their owner, a stranger and a familiar human - and found that dogs clearly miss their owners more than anyone else, and will wait behind the door they left through in anticipation of their return. Aw.
Although it's still unclear whether dogs are aware of the length of time they're left alone for, research suggests that they're more excited to greet their owner if they're left alone for two hours than 30 minutes. But between two and four hours there's not much difference.
But we do know that dogs process images faster than our slow human eyes do. Watch the episode above to find out more, and see what dogs are really doing while you're away - no wonder our phone bill is so high.
And find out more about whether dogs really understand what we're saying in the episode of It's Okay To Be Smart below.