my mallard on the nest in the garden (with my chicken eggs under her as well as her own!) has wondered off. i thought maybe shed gone for a bite to eat but hasnt came back after 2 hours. is this normal??? wont the eggs go cold? (its pouring down here and very cold) should i bring the eggs in??? shes been sitting for 2 weeks now..seems such a waste to let the chicks die? or is 2 hours without 'mum' ok??