TUCSON - Nearly 70 bats have been found dead in Tucson and Arizona Game and Fish officials are searching for answers.

One possibility is unseasonably warm temperatures in the city.

Game and Fish officials say the bats are Mexican free-tailed and should have migrated to Mexico two months ago.

The Arizona Daily Star says a man walking his dog Monday morning discovered the bat carcasses. They were strewn across a walking path that runs under a bridge on East Speedway where the road crosses the Pantano Wash.

Seven of the bats found on the ground were alive. All of the dead bats and three live ones were sent to the Arizona Department of Health Services laboratory in Phoenix for rabies testing.

Investigators could find no evidence of foul play in the death of the bats.