A budding entrepreneur - who is 'obsessed with being an adult' - has set up his own business returning dustbins to his neighbours ... so he could buy himself a dirt bike.Liam Roller, seven, has been labouring since December last year to set up 'Liam's Dumpsta Service' returning his neighbours' dustbins after the binmen come.He soon had 11 customers in his neighbourhood, each paying him $1-2 per bin, and now earns around $15-a-week.Little Liam's business has been so successful he was able to pay a hefty deposit - and ride away - on his $280 dirt bike within six weeks - and he's now saving for pocket money. Mum Angela Roller, 33, said: "He is very particular and type A. He likes routine, predictability and responsibility.SWNS