Jason Scott Falbo II, 24, was mowing lawns in Muscovy, USA, when he spotted a mother duck and her eleven ducklings.
He then aimed his ride-on lawnmower at the birds, killing several of them instantly.
Faldo then reversed over the remaining ducklings, leaving several more of the baby birds dead.
According to the Palm Beach Post, the mother duck and four ducklings managed to get to the safety of the lake, but two of the young birds later drowned from injuries.
Boyd Jentzsch, who had been feeding the birds with his wife and children when Falbo massacred the animals, told an animal control officer he confronted Falbo after the mower scattered pieces of the ducklings all over the grass.
Falbo's reply, according to The Sun Sentinel, was: "They were in my path so I just kept mowing."
He has since been found guilty of nine counts of felony cruelty to animals.
Faldo also has to perform 10 hours of community service a month and have a mental health exam within 30 days of getting out of jail.
He has two years to pay $669 in fines and court costs - and after he’s set free he must not own “any animals of any kind”, nor will he be allowed to live with anyone who keeps animals.
Speaking with the Palm Beach Post, Jentzch said that he felt the sentence was too lenient.
“They should have just thrown away the keys,” he said. “There is no justification for what he’s done.
“Just seeing the look on his face, it told me he was a very violent person inside.”