John Ball Zoo

Dan Hemmann



He started as a Zookeeper at John Ball Zoo on April Fool’s Day in 2001.  When he started he primarily took care of the educational animals in Red’s Hobby Farm.  Now he splits his time between making diets for the animals in the commissary and taking care of the monkeys and reptiles in the Tropics building.  He grew up in St. Louis and received his B.S. in Biology from Truman State University in northeast Missouri and a M.S. in Entomology at the University of Kentucky.  Before coming to John Ball, he worked in the Insectarium and Children’s Zoo at the St. Louis Zoo and in the Hamill Family Play Zoo at the Brookfield Zoo.   Outside of work, Dan likes spending time with his wife, daughter, dog, two rabbits, four cats, and two fish tanks.  He’s also a big comic book fan and a proud member of F.O.A.M. (the Friends of Aquaman).

Posts by Dan

Meet Gerald & Betty


With Independence Day coming up this is a great time to focus on our two Bald Eagles, Gerald and Betty.

Gerald and Betty have been long time fixtures at the zoo, arriving here in 1988 from Dickerson Park Zoo in Springfield, Missouri.  In 1995 a new bald eagle enclosure was built near the front of the zoo as part of the aquarium construction.  They have been there ever since.

Bald EaglesJohn Ball Zoo History

Do You Eat Like A Chimpanzee???


At the zoo we feed our seven chimpanzees a nutritionally complete diet.  But how much do our chimps eat compared to an average American family, assuming your family (like our chimp family) has seven people?

What Is This Strange Thing Crawling Around My House?"


“What is this?” is a very common question I hear.  As the resident entomologist (someone who studies insects) people bring me all manner of insects, spiders, and other so-called creepy crawlies to identify.  

 Here’s your chance to experience what it’s like to be zoo entomologist.  Someone comes up to you and shows you a picture of something running around in their bathtub.  What is it?

EntomologyInsectsZookeeper Dan Hemmann

Karner Blue Butterfly: Status Endangered


What comes to mind when you think of an endangered species?  Do you think of Chimpanzees living in the jungles of Africa?  Maybe giant pandas in the bamboo forests of China?  Perhaps even the Komodo Dragons of Indonesia?  John Ball Zoo makes a difference in conservation efforts worldwide, but we also play a role in conservation right at home.

ButterfliesKarner BlueLupineZookeeper Dan Hemmann

How Did You Even Notice That??


“How did you even notice that?”   Recently I  had two people ask me that same question.  I was telling them about an awesome pseudoscorpion I found crawling around the Hoofstock Building at the zoo.
“It was huge,” I was telling them.  “Probably about the size of a sesame seed.”

Dan Hemmann