Old Tunnel State Park

The Bat Emergence

Arty image of bats in motion against a twilit sky

Watching a colony of Mexican free-tailed bats emerge is quite an experience.

During emergence, the bats spiral upwards in a counter-clockwise direction to gain altitude. Aerial predators, such as red-tailed hawks, sometimes catch bats as they emerge. Terrestrial predators, such as raccoons, feed on fallen bats.

The bats can travel as high as 10,000 feet and as far as 60 miles each night to feed on agricultural pests such as the corn earworm (a.k.a. cotton bollworm), cutworm and webworm moths.

Each bat can eat its weight in insects nightly. The Old Tunnel colony may devour over 25 tons of moths per night!

How to view

Bats reside in the tunnel from May to October.

Rangers lead nightly programs on bats in these months, focusing on the fascinating life history of the Mexican free-tailed bat. Programs begin 30 minutes to an hour before the bats emerge.

Bring binoculars for closer views!

Advance tickets required

Buy tickets online or by calling the Customer Service Center up to 60 days before your visit. Show tickets or email confirmations on your phone at the gate.

Purchase tickets in advance; we do not sell tickets on-site. Space is limited so buy yours early! You cannot enter without a ticket.

We have two viewing areas with differing ticket prices:

  • Upper area: $2 per person (all ages)
  • Lower area: $5 per person (4 and up – children under four are not allowed in this area due to bats’ sensitivity to noise)

Every person (including children) must have a ticket.

The park closes at 5 p.m. year-round. Only ticket-holders can be in the park for bat viewings after 5 p.m.

Viewing areas

Upper area

People watching bats in sky as night fallsThe upper area is next to the parking lot. From here, you can take in the rugged beauty of the Texas Hill Country.

The best bat viewing from this area is in August and September, when bats emerge earlier, and the sky is lighter. This is also a great vantage point for watching red-tailed hawks feeding on emerging bats. 

After the sun goes down, stay a while to enjoy the night sky!

The upper area is open nightly, May through October.

Lower area

Watching bats emerge up close is one of the most unique experiences in nature. Listen for millions of tiny wings flapping and feel a light wind stirred by bat wings.

The lower area is open Thursday through Sunday evenings, May through October.