Thai people believe that keeping monkeys happy brings good luck. So every year there's a day on which they have a special treat for monkeys called the Annual Monkey Feast. Hundreds of monkeys come from the mountains to "sit at" long buffet tables which are piled high with bananas, peanuts, watermelons and cabbage. 
Monkeys will be monkeys. So they fool around and fights break out. But nobody seems to care. Neither do the monkeys. They just stare back at the crowds of people who turn out to watch them. Then they continue to monkey around and have a good time.

fool/horse/monkey/goof/idle around 鬼混
keep animal 养
He came on a day when it was rainning.
treat sb to sth 请...客      It's my treat.我请客    The doctor treated me for my illness.治疗
dozens of 好几十   不说：tens of
hundreds of 好几百
thousands of 好几千
tens of thousands of 好几万
hundrds of thousands of 好几十万
Scores of people were standing in line to buy a ticket.  (旧式用法: twenties of)
line up 排队   don't cut in (line). 插队
buffet  自助餐厅
Boys will be boys. 本性难移
An idle youth, a needy age. 少壮不努力，老大徒伤悲