FERNDALE — A Ferndale pet shop owner pleaded guilty to assault and battery after police say he spanked two teenage girls who volunteered to help with animals at his store. Timmy Olson, 46, of Detroit owns the Tank Pet Shop, 3285 Hilton. He faced two misdemeanor counts of assault and battery after two Ferndale girls, ages 16 and 15, told police he spanked them with a paddle and his hand on occasion. Olson on Tuesday pleaded guilty to one count of assault and battery in Ferndale 43rd District Court and the second count was dismissed. "We got a report that he spanked them on the buttocks," said Ferndale Detective Ken Denmark. "He admitted spanking the teens, but said it was done only to discipline the girls when they acted badly in his store." The girls told their parents about the allegations in April, after Olson told them they were no longer welcome at the store, police said. The girls had volunteered to help feed the animals and clean cages at the store, which they did for about a month, Denmark said. "They also claimed he made inappropriate comments to them," he said. But Olson told police the girls would use vulgar language and make rude comments to passersby. After pleading guilty Olson was ordered to pay $325 in fines and court costs.