It's always heartwarming to see a father and son doing things together. Many of us look back on our childhood and recall those moments that meant a lot to us.

Dan Markham is just such a father, and he often is seen with his son, Lincoln, opening things and seeing what is inside. They have their own YouTube channel, "What's inside?"

Photo: YouTube/What's Inside?

The premise of the channel is easy to understand. They take random items and open them to see what is inside. This is not only something interesting for Lincoln, but his father probably learns a lot from it as well.

The YouTube channel wasn't started to get a lot of followers. It was part of a second-grade school project to look inside sports balls, but now they have taken things to the next level.

Some of the different things that have been opened by Dan and Lincoln include a media light, sneakers, a laptop, and even the rattle from a rattlesnake.

Photo: YouTube/What's Inside?

This isn't only a hobby any longer but rather, they may have made as much as $6 million from their YouTube channel, according to Naibuzz. They get about 80,000 views every day for a total of 1.2 billion views.

Although they have many videos, one of their most popular is when they opened a wasp nest. Dan and Lincoln are seen in the video along with a friend, Kai. At first, they tried to get a nest from their own backyard, but they only found one with many tiny wasps.

That is when they turned to the Internet and purchased a nest online. It was from Wisconsin and they found it on eBay. They loved opening the box, but when they saw what was on the inside, they were a little nervous.

Photo: YouTube/What's Inside?

The nest was about the size of a basketball, and they were concerned that there might be some wasps on the inside. Kai talked them into opening the nest, and Dan cut through it with a knife within a few minutes.

Fortunately, no wasps came flying out of the nest. They found the holes where the Wasps used to live, and it was a little worrisome to Lincoln, who had been stung a number of times in the past.

They continued to tear the nest apart and look inside. It's amazing what you can learn from just watching a video, and this video taught us a lot.