Australia is under siege. Our cities are under siege. And especially the central cores of our largest cities. And the insidious life form that is infiltrating every aspect of Australian life? Why that'd be babies of course.
Babies are everywhere and they are spreading like wildfire. Babies are increasing in number and they are venturing far from their traditional habitat. Oh yes, babies are on the move and they are looking to colonise new territories. They are looking for new lands to conquer. Babies will be constrained and contained not a moment longer. This nation's babies are up for a none-too-quiet revolution.
Consider the evidence. A decade ago this nation was producing just 250,000 babies a year. Today that number is closer to 310,000. Every year for a decade an extra 6000 babies have infiltrated the Australian continent. The baby business is booming but there's so much more to this than the baby life form quietly upping their numbers. 
Babies are on the move. Admittedly this movement includes toddlers as well as babies. In fact, it's the whole of the 0-4 year cohort (otherwise known as the preschool gang) that is on the move. They are all in on the same revolution.
This lot used to be content to live out their childhood in suburban places like Melbourne's City of Wyndham and Sydney's City of Blacktown where they can still comprise up to 10 per cent of the population.
These traditional habitats for babies were, and in some quarters still are, known collectively as Nappy Valley and for very good reason. Such places offer cheap house-and-land packages where couples with kids might flourish amid suburbia's peace and tranquillity.
But Nappy Valley is no longer the sole preserve of babies. Babies are upping and offing to new lands or at least to other parts of the city. Babies are beginning a long and arduous migration that is taking them deep inside the inner-city's hipster heartland and towards the lights of the city centre. The CBD and surrounding suburbs appear to be the young migrant's preferred destination and many have already made the trek.
A decade ago just 2235 kids aged 0-4 lived inside the City of Melbourne. Today this numbers stands at an impressive 3910. Over the last decade about 1700 extra babies and toddlers have somehow surfaced in the City of Melbourne. It's a similar story in the City of Sydney where the population aged 0-4 has jumped 3500 to reach 7700 in just ten years.
That's 170 extra babies in central Melbourne and 350 extra babies in central Sydney every year for a decade. These babies are clearly up to something and I am determined to get to the bottom of it.
Why are babies on the move? For more than 50 years babies happily eschewed the inner city; they were drawn by the allure of the light and space and modernity of low-density suburbia. What Australian baby wouldn't want his own yard?
But apparently this is no longer the case. Babies are demanding more, so much more. Babies want proximity to the city centre so that both parents might have access to better-paying jobs. Babies also want proximity to the city centre so they can live a lifestyle that is sophisticated and that speaks to their modern-day urbanesque values. Babies are gettin' all urban sophisticated.
And you can't be all urban sophisticated living out in the suburbs. And so, as if driven by a primal survival instinct, babies are on the move and are expected to be on the move for at least another decade. Official projections place the City of Sydney's 0-4 population at an extra 3000 by 2024, while for the City of Melbourne the rise is expected to be 3500. That's between 300 and 350 kids aged 0-4 years added to the CBD and surrounding suburbs every year for another decade. The great baby migration is upon us. This raises an interesting question. At some point in the future both the City of Sydney and the City of Melbourne will reach the condition known as Peak Baby.
I say that Peak Baby won't be reached in Sydney and Melbourne until the late 2020s, which means that for the next decade local councils will have to manage escalating expectations for baby services. And if babies don't get what they want they can make life difficult. Very difficult!
But there is more to the great baby migration than the trek of 0-4-year-olds from the suburbs to the CBD. Some babies grow weary of the journey and get diverted along the way. There are in fact two baby islands sitting a few kilometres to the west of the Sydney CBD and the Melbourne CBD. I'm talking about Leichhardt and Maribyrnong as baby hot spots.
For some babies the CBD and its immediate environs are a step too far. For some babies the allure of an intervening lifestyle opportunity is just too tempting: such places are not suburban-dull, but nor are they CBD-harsh. Sydney's Lilyfield and Melbourne's Footscray rise like fertile baby islands that stand proud against a hostile sea of inner-city childlessness.
The great baby migration began a decade ago and perhaps has another decade to run. By the end of the 2020s the inner city may well be home to a new species of baby that survives and thrives amid a high-rise environment.
At some point in the future CBD hipsters will procreate and when this frenzied mating moment arrives they will strengthen the gene pool, and the inner-city habitat, of Australia's brand new revolutionary life form known as big city babies.Bernard Salt is a KPMG Partner and adjunct professor at Curtin University Business School; bsalt@kpmg.com.au; mapping by Cody Phelan of KPMG Demographics