A shelter in Missouri had an unexpected influx of feline residents earlier this week when 18 cats were abandoned outside the facility in two large plastic tubs.

On Tuesday, the large containers were dropped in a resident’s front yard across the road from the Stray Rescue of St. Louis shelter.

“A man saw someone out of his window dropping the totes off and pulling away,” the shelter’s Natalie Thomson told Newsweek.

The concerned neighbor noticed air holes in the containers and immediately loaded the first one into his car and drove it to Stray Rescue. “He said the second tub didn’t fit in his car, so he left to get it and bring it back,” Thomson said.

In total, the two containers held 18 cats—eight older kittens in one and two adult cats with eight tiny, nursing kittens in the other. Despite their shocking abandonment, all of the cats were surprisingly in good health.

“We were so nervous opening the lids,” Thomson said, expressing the anxiety the staff felt, not knowing what they might find inside. “We’re so thankful they got to us when they did.”