What Do You Feed Spiders?

My friend is migrating to another country and he asked if I would be willing to take care of his tarantula. I haven't answered him yet because I still have to consult my husband. We have kids in the house plus a dog and cat so I do not think he will agree. It is interesting though and will try to convince him. We can just put locks in its aquarium/container. It made me wonder though what pet spiders eat. Where will I get spider food? Do I have to give the spider live insects or something?

Live insects for sure. When I was in the high school, we had a live tarantula in our biology lab. The teacher was feeding it with live crickets. You can buy live crickets from many pet stores either online or locally. You can also buy mealworm and other types of feeder insects from pet stores.

If you are unable to buy the feeder insects, you can always catch some yourself. Although I have never owned a tarantula myself, I have a little experience with feeding a spider in captivity with live house flies I caught.

How big is this tarantula?
The one in our biology lab was as big as my hand. The little spider I had for a while was smaller than my pinky finger nail.

Just guessing I would say live insects, like grasshoppers, crickets etc. You can catch your own Grasshoppers, but if you go to a pet store I am sure they could tell you.

What does your friend that owns the spider say he feeds it?

Keep continuing to feed it what it has been fed all this time. If possible, keep it in the same container it was in before. Or if you are buying a larger or different one, take some things out of it's previous home and stick it in the new one.
If he was eating insects brought from a particular store before, you could try to keep buying it from the same store, if possible.

My son had a tarantula. We fed it crickets mostly but in the event that a fly or some other insect had the misfortune to find its way into the house, the spider had some variation in its diet. If I were able to look at it objectively, I would have to admit that it was an attractive looking spider. By that, I mean that its coloration was pretty, but it was still a spider and I was never entirely comfortable with it.