Many students returned back to school in Colorado this week, but at Columbine Elementary in Longmont, kids weren't the ones hanging out inside the building following the summer break.

Several days ago, a construction crew working at Columbine Elementary School had a frightening surprise when they came across a colony of bats that were using the school as a home.

During the school's renovation project, workers had removed three exterior lights, which left holes open to the inside of the building. On the same day that the lights were removed, the crew also took down the trim around the outside of the building. The trim, however, was also doubling as a roost for a bunch of bats, and when the workers saw them, they became scared and left for the day – without covering up the holes that were left from the light removals.

No longer having their roost, the bats had to land somewhere, so they made their way inside the school, through the open holes where the lights had previously been. Not only were the holes close to their original roosting site, but the easy access provided the bats with a cave of sorts, where they could continue to roost.

After the bats were discovered, the supervisor of the construction crew sealed up the holes on the building where they had flown in and then called the Northern Colorado Wildlife Center to come out and humanely remove them.

According to the NoCo Wildlife Center, 17 of the bats were scattered around the three-story school, hanging from various ceilings and walls. Luckily, since it was still summer break, the teachers all had their classroom doors closed. Wildlife rescuers walked the halls and used a net to safely scoop the bats into wildlife transportation containers.

The following day, the principal of Columbine Elementary called back, saying they'd found a straggler bat still lingering inside.

After receiving some hydration, the original 17 bats were released later in the evening on the same date that they were rescued. The lone bat that was removed on the second day was released back in the same spot so that he could reunite with his colony. None of them were injured.

The Northern Colorado Wildlife Center explained that the situation could have been prevented if the construction crew had covered the holes into the building as soon as they made them. Openings like that are a welcome entrance for all kinds of animals, such as birds and bats. Center staff also noted that it would have helped to hang up a bat box somewhere nearby before removing the original roost so that the bats could have just transitioned into that.

The Northern Colorado Wildlife Center said that people are more than welcome to message them on Facebook if they have found a bat in Northern Colorado that requires being removed.

School Resource Officer Mike Welcomes Students Back to Central High School

SRO Mike is celebrating his 'Senior Year' at Central High School and was on hand to welcome the students back to school this week.

A List of Grand Valley Elementary Schools