Put the words into the right order: if night that locked up the chickens eaten at the fox not would have they them

If they locked up the chickens that night, the fox would not have eaten them. - Если бы они закрыли цыплят на замок в ту ночь, лиса не съела бы их.

at – не знаю куда ставить. Можно сказать at night или that night.