My elderly parents own a detached1930s bungalow. One wall of the bungalow is built on the boundary between them and the next door neighbour, all the properties in the street are built in the same way.
Where the guttering is, at the top of this wall, there is no drain for a downpipe to drain into so the downpipe sort of comes down the wall at an angle and then when it reaches the ground it has been extended so that it basically just lies on the ground and drains off underneath a hedge in the back garden.
Next door neighbour hasn't done any gardening for at least 20 years and has intermittent problems with rats in his garden. On a few occasions over the years parents have complained of being woken at night time by scratching noise in the cavity wall in their bedroom and even something running around their bedroom. They've been too frightened to turn a light on and just hide under the blankets!
I am wondering if rats are getting into this drain pipe and somehow getting access into the cavity wall. Is there something I can buy to stick up the end of the drain pipe to stop rats getting access in to it but at the same time allowing rainwater to drain out of it.
The next door neighbour is quite obstructive and doesn't want any of us going on to his property to check the condition of the wall or do any sort of maintenance work when required so it's not easy to see if there are any holes in that walls where the rats might be getting in.