I agree, bug-bombing the place would work. Maybe they don’t have bug bombs in the UK, tho?
And btw, those do not look like spider bites. At all.
*** Maybe they don’t have bug bombs in the UK, tho? ***
Not sure about the UK, but some years back when I used to visit friends in BiH, they always asked me to bring loads of Bug Bombs as they weren’t allowed there.
Not sure if the insecticide or the propellant was the reason they didn’t sell them there.