Dillon and the Spider

Dillon and Charlee came down stairs excited today because they found a spider and were eager to catch it. Dillon got a container with a lid and they both left to get the spider.
A bit of time past and they came running back in and said that they had put a dead fly they found in the container so the spider could eat once they caught it....

Me: Well that's great, but spiders really only eat living flies because they like the fresh blood.

Dillon: Well maybe there's still a little blood left in this fly.

Me: I'm not sure baby, that one's been dead quite a while, you really need a living fly.

Dillon: That's going to be pretty tricky... I guess we'll just have to give it some of Charlee's blood.