AUSTIN (KXAN) — A southeast Austin bar taught a class on how to care for some of our most loyal and beloved creatures.

The Buzz Mill, in partnership with ecologist Merlin Tuttle’s Bat Conservation, held a class on how to build bat houses. Tuttle dedicated his career to bat conservation, researching the species across the world for more than 60 years.

The conservation said these houses are important, because bat populations are declining, in large part due to a lack of available roosts.

“When you have a bat house and it’s occupied, it’s a really fun activity to have friends over and watch the bats come out, and it’s an easy way to teach people about how important bats are just to have them around,” Teresa Nichta, who is a co-founder of Merlin Tuttle’s bat conservation, said.

Austin is home to the largest urban bat colony in the world. Texas Parks and Wildlife estimates there are about 1.5 million bats living under the Congress Avenue bridge.

This year, the Austin bats made an earlier appearance downtown due to the early start to spring and warm temperatures. The Austin Bat Refuge reported they started arriving during the third week of February.

The refuge said it wasn’t just the Mexican free-tailed bats that showed up, but also bats from other colonies using Congress Avenue as a stopover on their way to other locations.