A brief lesson in the laws of nature

Yesterday we went for an outing to Formby to view the red squirrels and, in order to capture the imagination of our somewhat reluctant eldest child, to look for the Faraway Tree. Despite squally and unpredictable weather, bad traffic and our post wedding anniversary hangovers, this was a very enjoyable experience. The squirrels were out, ears up like little alien antennae, there was plenty of mud for little wellies to wander in and the promise of ice cream kept spirits high. Much discussion and debate ensued about red and grey squirrels. It went something like this:
Dom: "But why are these squirrels red and normal squirrels are grey?"
Me: "Well, they were here, in Britain, first, but then some grey ones came to live here and they took over."
Dom: "How did they take over, Mummy?"
Me: "Well, they were bigger than these red ones and very hungry so they ate all the food."
Dom: "But why did they eat all the food and not leave any for the red ones?"
Me: "Um. Because they were hungry and they weren't thinking about the red ones."
Max: "That's not very kind."
Chris: "And also, the kind of trees we have in this country changed and the red squirrels only like living in pine trees like these."
This was a good diversionary tactic from Chris and much tree examining ("But why do they call the leaves needles Daddy?) ensued but yet, ten minutes later, it all began again.....
Dom: "Mummy"
Me: "Yes Dominic."
Dom: "But why didn't the grey squirrels care about the red squirrels?"
Me: "Well because they are animals. That is one of the differences between people and animals. It's called the survival of the fittest......"
There is often a point in my conversations with Dominic that I feel that I am either talking total drivel or am so overly conscientious about trying to give him a proper answer that I end up saying things that are just going to keep his questions increasing rather than getting me off the hook. This is one such moment.