The little sh1ts are a pain in the a$$. I put the reminants of a curry in the bin a few days ago and the next morning there were an army of them going from a window frame downstairs in a bedroom all the way up the stairs across the living room and into the bin in the kitchen. And the lid of the bin was closed, unreal.
Normally the spray with the little metal pin extention thingy does the trick by spraying all the doors and nooks and crannies on the ground etc. That a few times a week and not leaving any nice snacks lying around for them has generally worked for me. The other bedroom wasn't sprayed for a while hence why they got in.
Gecko