Just... everywhere.
That noise outside? You bet your arse it's a fox.
That feeling at the back of your neck? A garden spider has definitely set up camp.
... wouldn't an increase in both (a steady increase, not just a one-season bump) be a positive signal indicating environment's health/biodiversity?
Sure, both have other externalities (foxes are smart & are getting integrated in human ecosystems, spider population can be upheld by a single species, like an unbalanced amount of mosquitoes + warming climates increase the survivability of both), but it's better to have more of them, right?