Belleville, Michigan - Two staff members and a volunteer at the shelter, Friends of Michigan Animals Rescue, noticed a box at the end of their driveway shortly after arriving. A heartbreaking note scribbled on the box said it all: "Mom cat 3 BBY kittens CANNOT AFFORD."

The concerned shelter workers rushed to bring the box inside before opening it, as they told the Dodo.

"We weren't initially sure what we were dealing with, and we didn't want to risk any of the cats jumping out or getting loose, so we brought the box inside to our Cat Haven before opening it,” Michelle Eastlake, operations manager at Friends of Michigan Animals Rescue, explained.

When the staff opened the sealed cardboard box, they found exactly what the note said they would: a mama cat and three babies. They'd been nervous because the box had no ventilation holes – and no one knew how long it had been sitting out in the cold.

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But on closer inspection, the women began to suspect something. "We honestly believe whoever left them there may have been waiting for our morning staff and volunteers to arrive,” Eastlake said.

“Based on how warm everyone still was when we found them, we're estimating they were outside for only about 20 minutes before we discovered them.”

Even though the mama cat had likely only been in the box for a short time, she seemed relieved to be rescued. Her kittens were a little frightened.

The four cats are settling into the shelter. The staff will keep them until the kittens are weaned and ready to move on to their forever homes.