I personally wouldn't buy a 20kg bag if you only have 2 rabbits. Do you store the food in a plastic container or is it just left in the bag? Surely 20kg for 2 rabbits would last forever? I have 4 rabbits including 2 giants and 1 poorly girl who i feed 2 handfuls of food a day to, and i still only use around 4kg a month. So if you say 2/3kg a month for 2 rabbits, you are looking at the bag lasting at least 8 months, which is far too long for a bag of food to be left open IMO x