incoming pests

My neighbour who is a spritely 86 year old is having a torrid time with incoming pests.
I have been troubled with wood lice myself but they are just a nuisance each time the back door is opened.
However, Betty is having what she terms an infestation of what appear to be small,thin dark brown worms.
They range from less than an inch to sometimes an inch and a half and are to be found coming in the back,and indeed,the front of the house.
She has even discovered two in the upstairs of the house.
As she is the only house that appears to have this problem no-one knows what exactly they are or where they come from.
Would the Garden Forum be able to enlighten me on this question?
Are these coming from a certain plant and what would stop this.
She is getting quite alarmed now.
Thank you in anticipation of your help.

 

Problem solved.
They were millipedes and decided to nest below the rotting timber of the threshold.
Bleach for now and new wood next.
Thanks