Found chicks today

[Woeismethischristmas]

So we have some chickens and a cockerel. Found some chicks today, children clearly doing a crappy job of egg hunting! They have feathers and are fluffy rather than newly hatched. The chickens have the run of a small field and tend to roam but run back for food. Should I leave the chicks with thier mum we've caught 2 but think there were 5 and popped them in a box but maybe we should leave them in the field? There's also ducks and 2 geese in there if it makes a difference. Mainly worried about rats from neighbouring fields as I assume its the hardy ones that got to this stage.