we did this sometimes for safety , like when some of the bigger gangs was at war and we needed to stay out of the way , or when the police was keen on nabbing us , 'cause of what we 'd been up to , but mostly we did it 'cause when we was up there we could spy out any profitable mischief down below-a pie cooling on a windowsill , or some clothing hung out to dry that we could pinch and sell to the ragman .