Bat Caves are Don't Starve Together exclusive objects found in the Caves. They spawn Batilisks, thus allowing players to determine if the area contains Batilisks while also making them renewable in the Caves.
When a player comes close to a Bat Cave, a Batilisk will spawn every 20 sec to a maximum of 4 Batilisks. It takes 2 minutes for a Bat Cave to respawn a single Batilisk.
Before Bat Caves were added, Batilisks were not renewable underground. They are renewable in the overworld, since Sinkholes spawn Batilisks at Dusk and Night.