United Kingdom, Sept. 26 -- Miranda Kerr's middle sons are like a "built in playdate" due to being so close in age.

The Australian model has four kids - Flynn, 15, with ex Orlando Bloom and Hart, eight, Myles, six and two-year-old Pierre with husband Evan Spiegel - who keep her "very busy".

Luckily, Miranda's middle sons get on so well that they keep each other occupied by playing together 24/7.

On the Big Talk podcast, Miranda said: "It's very busy because I have the full spectrum of age from 2, 6, 8 and 15. Having a 2 year old whilst having a teenager and then having the 6 and 8 year old. 95 percent of the time my 6 and 8 year old are a built-in play date so that's pretty fun."

Things can get a bit rough though, as Miranda laughed: ...