Certainly
Steatoda sp. shape as opposed to the 'real' ones, but the 'red' bits interest me, there is some red in one of your photo's though it's a bit blurred. Do they all appear the same as one of the other shots doesn't show any red and looks like
S. grossa I'd say.
I'll await further photo's.
Welcome to WAB and as Venger says leave them be, they've probably been there a while and done no harm. Just treat with respect
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No.9 Spider