Invasion of Britain, page-38

The only solution to invasion by stealth is to out-breed them. As Costello said - have 1 for mum 1 for dad and 1 for Australia....and
another one for homeland defence. In the end the elite won't have to increase immigration to grow their economy and we can
keep invaders at a manageable percentage.
Kids are great fun anyway...just work a bit harder or give up some luxury and knock another one out.