If you break down a gnat mound, the gnat swarm spawned from it will start a timer at the end of which it will play an animation and lay down a new mound. However, after that first rebuild, this timer is apparently not reset, as the swarm will instantly rebuild after you break this home down. This persists until the world is saved, closed, and reloaded.
Steps to Reproduce
Destroy a mound, wait for the gnat swarm to lay down a new one, and then destroy that one.
Destroy a mound, wait for the gnat swarm to lay down a new one, and then destroy that one.
A developer has marked this issue as fixed. This means that the issue has been addressed in the current development build and will likely be in the next update.