While there are countless reasons your dog or cat might pee, like a lack of walks or a dirty litter box, peeing outside of designated areas may be a sign that your animal is upset. For cats, peeing outside the litter box is often a means of marking their territory, often in response to another animal in the house. "When cats are upset, they are likely to 'act out' by urinating or defecating in inappropriate places such as on the owner's bed," says Dr. Gary Richter, a veterinary health expert with Rover.com.

"Cats are well known for their tendency towards displaced aggression. In other words, if a cat is upset by something they are likely to lash out at the nearest person or animal." For dogs who pee indoors, this behavior is often related to a lack of physical exercise or anxiety, both of which humans can help attenuate with the help of a vet or trainer.

2. THEY CHEW UP YOUR STUFF

While dogs have an innate desire to chew, their destructive behavior may be the result of either fear, lack of attention, or separation anxiety. The solution? Check in with your vet to make sure it's not a medical issue, and take Fido to a behaviorist to get to the bottom of it. And before you bring home a pup, make sure you've read up on the 10 Things You Need to Know Before Adopting a Shelter Dog.

Is your dog or cat suddenly treating your whole house like his personal powder room? It could be a sign that he's not so happy about your behavior. If your pet is pooping wherever he pleases, it may be a sign that you're not walking them or changing their litter box frequently enough. It could also be a sign your pet is fearful, so consider addressing your own behaviors, like yelling or slamming doors, that could make them scared. And if you're on the fence about getting an animal of your own, the 15 Amazing Benefits of Adopting a Pet will have you convinced!