"It's so funny to see just how zoned in and focused they are because this is their first experience," Hicks said. "They're so locked in that I'll tell them a joke and they're like, 'Uh, can I laugh?' But it comes with time and [they'll] get more comfortable [once they] get a grasp on the system. That's really what the big focus is for them, especially on our defense, is picking up all the stuff that everybody else already knows."

Rookie outside linebacker Kylie Fitts, a sixth-round draft pick from Utah, enjoyed practicing alongside some players he grew up watching.

"It was a lot faster than the rookie minicamp for sure," Fitts said. "Calls were coming in a lot faster. So you've got to really focus in and know your assignment and know your technique. But it felt good. After a few plays, I started getting used to it."

Acho is impressed with the strides the Bears rookies have already made.

"They seem really advanced," Acho said. "At least in our room, the OLB room, a lot of guys seem way ahead of what you would expect from a guy who's a week in or a couple of days in, so it's exciting."

Acho has fond memories of his rookie season with the Arizona Cardinals in 2011.

"I was treated really well thankfully," he said. "I knew guys that I could trust. [Safety] Adrian Wilson and [linebacker] Clark Haggans were two guys that really taught me well. People talk about treating others the way you want to be treated. I had veterans who treated me really well, so I want to do the same."

Hicks was a rookie with the New Orleans Saints in 2012.