Local 4's Dr. Frank McGeorge made surprise visits to several families in Royal Oak and asked them to show him their clutter.

Tom Mervak and wife have two cars in their driveway that have never seen the inside of their two-car garage.

"I couldn't tell you when we ever parked a car in this garage. The garage was built for storage," said Mervak.

The Mervak's garage is filled with clutter from their six grown children and a few "antiques" of their own, including their first television from 1973.

"It still works, why get rid of it?" said Mervak.

Diane LaBuda and her husband Brian have two kids and an overwhelming amount of stuff to go along with them. They said dealing with clutter does add stress.

"Seeing it all the time is a bit exhausting. Overwhelming. You don't know what to do after a while. How to stay on top of it and how to get rid of it," said Diane LaBuda.

So why do we hang onto so much stuff? Experts said the urge to hold onto material goods begins deep in our brain.

"There's actually a lot of research showing that emotional effects are a primary reason why people hold on to items. So anxiety is a major one," said Dr. Stephanie Preston, an assistant professor of psychology at the University of Michigan.

Preston has done extensive research into human and animal decision-making and said humans actually have a lot in common with squirrels.

"Squirrels, contrary to some people's belief, are doing very complex economic decisions. Their food is available in the fall, and they have to live off the rest of the year on these decisions," said Preston. "The same region activated when squirrels make decisions to hoard nuts, people are activating when they make a decision to save something for the future."

In other words, your brain is telling you: "I might need this someday in the future, so I better not get rid of it."

"People have anxiety that if they get rid of something, later it will turn out that they need it and they made a mistake. So in keeping the item, they're preventing this possible future problem that they mistakenly got rid of something," said Preston.

Preston said we keep other items because of the memories associated with them.

"When your children bring home drawings and homework assignments, you feel an emotional attachment to the items, and it can make it hard to make any decisions to get rid of things like that," said Preston.

But experts warned, if stuff keeps piling up, it can quickly become stressful.

"It's sort of a vicious cycle, so if you have this tendency to not want to get rid of something, out of fear, or anxiety, or an emotional attachment, then the amount of stuff can accumulate to the point where then it's scary, it's overwhelming, and you don't want to deal with it," said Preston.

In extreme situations, this can lead to hoarding. But experts say even ordinary clutter can have a negative impact on your life, including your ability to get things done and socialize with others.

"People spend significant amounts of time each day looking for items that are somewhere in their home," said Preston. "And when people are embarrassed about the amount of clutter, or the accumulated stuff in their home, they don't want to invite people over."

Clutter can run in the family. Brian LaBuda admitted, that's true for him.

"I keep too much stuff that's too old. I got that from my mom. My mom was a pack rat too," said LaBuda.

So how can we begin to let go of items, even when our brain is telling us to hold on?

Preston said it's important to start small and be realistic.

"Don't try to tackle the whole problem at once because then you'll set yourself up for failure," said Preston. "You want to start with things that are the most irritating to you, but develop a system that works for you. Don't try to have the perfect system, if it's not realistic to follow through on that."

Organizing experts offered this advice to help tackle clutter:

Schedule time to clean out clutter, even if it's just a few minutes at a time.

Most clutter comes from indecision. If you really need to keep an item, assign it a place to go. If there's no place for it, create a place by getting rid of something else.

Group items of sentimental value together. Once you can see it all in one place, you may realize you don't need all of it to remember a lost loved one or those special childhood memories.

As you tackle your bigger messes, spend 15 minutes a day just picking up your home to prevent new clutter from accumulating.

If it's all too much to tackle, consider hiring a professional organizer to help you get started.

If your spouse is the pack rat, Preston said it's wise to approach the topic carefully and focus on solutions, instead of accusations.

"You want to focus the conversation on the things that are bothering you the most and what are some practical ways we could possibly address this," said Preston. "You don't start the conversation, or focus the conversation, with your significant other on how irritating the behavior is because that's just going to cause more relationship stress."

Preston also shared her personal trick for keeping clutter under control.

"I routinely invite people into my home, so I know at least I will create an external pressure for me to tackle the problem once every couple weeks, but it never gets too far out of control."

Preston said some clutter is perfectly normal, but when your collection of stuff starts to have a negative affect on your family and your ability to get things done, it's time to start clearing stuff out.

For more advice on how to start clearing out clutter, click here.

To learn more about the National Association of Professional Organizers, click here.