Blocked gully full of brambles and trees

Really abandoned gully to rear of my property and the two properties to the left of me , causing huge ongoing problem with rats, I have my 3 year old nieces at weekends and am Afraid to let them out the back , the end of the gully gate lands in my garden and would be ideal for my son to come through that way with his bike if it was cleared as well as I have no side entrance and a very small house, I’ve spent a lot of money having my back garden done with slabs and Astro grass and I’m scared to put washing out let alone sit outside due to rats, there is no rubbish or anything to attract the rats in my garden I know next door has all different birds and throws seeds etc weather that’s attracting them I don’t know but it’s reslky started to get me down now, I suffer with mental health issues and used to love going out in the garden to relax but now I’m just too afraid.