There was a huge spider, three inches across, in my shower cubicle. That's not a good place for a spider, because it could get washed down the drain, and I feel sure that it wouldn't like that. And a ladybird on the floor. So I got the spider box.
First I captured the ladybird, and threw it out of the window; I wanted to give it a head start over the spider.
Then the spider, and while I was capturing the spider, I noticed another, tiny spider, which was optimistically spinnng a web in a corner of the shower cubicle. So I deported the large spider, then the small one. They'll both do better outside than in.