MILWAUKEE -- Volunteers are what make many organizations thrive, and one at the Milwaukee County Zoo is making his mark one paper at a time.

If you've ever seen animals, like apes, playing with shredded paper at the zoo, then you've seen Matthew Grulke's work.

The 22-year-old has volunteered nearly 500 hours over the last three years and most of his time has been spent shredding papers in the Zoological Society office.

"For me, this is my second house," said Matthew. "I feel so at home."

Matthew started working at the zoo in 2006, restocking the gift shop. After a year, he decided he ought to volunteer his time with the Zoological Society.

He works two to three hours a week, shredding paper that is given to animals, like apes, to make beds and play in.

"I love it here," said Matthew. "I'd like to work more hours."

Zookeeper Stacy Whitaker is on the receiving end of Matthew's work. He delivers more than four bags to her each time he volunteers.

"He's fulfilling a need for us to have things like that around," said Whitaker. "He's definitely an enjoyment and very helpful. He's always full of jokes too."

Matthew's mom, Linda, says he's been going to the zoo ever since he was a little guy and working there makes it even more special now.

She says it teaches her son, who has Down syndrome, responsibility and gives him a sense of pride.

"He does a lot of things I never thought he'd be able to do," said Linda. "He does it willingly and gladly and has a good time doing it. I'm very proud."

"I feel very comfortable here," said Matthew.

His mother can't even get him to leave a few minutes early because Matthew is so passionate about giving his time.

"Matt is an incredible young man. He's funny. He's hard working. He's a joy to be around and he puts a smile on everyone's face," said Zoological Society Marketing Coordinator Julia Kolker.

She's gotten to know Matthew while working in the office and says the zoo couldn't run without volunteers like him.

"I like to think that his volunteering would be a life skill-that he can do something, somewhere forever," said Linda. "So he can make things better for the general good."

If you're interested in volunteering with the Zoological Society, log onto www.zoosociety.org.