Ok, so what you can see in my pictures above are eggs and post-embryos. Post-embryos are affectionately nicknamed Eggs with Legs (EWLs). Spiders don't "hatch", they molt. So an EWL molts out of the egg. The outer shell of the egg is all that is discarded, and all of the energy stored in the egg is still in the egg portion of the EWL, which will become the spider's abdomen. After the EWL molts it becomes a 1st Instar spiderling and looks more like a proper spider. Again, it only molts off the outer layer of "skin" (exoskeleton), and all of the energy stores inside, still remains inside it's abdomen. All of my spiderlings from above are now 1st instar, but I don't have a picture of them yet, I can take one tonight. They are basically too small and not developed enough to fend for themselves and eat, but they have enough fat stores to last them until they molt into 2nd Instars. After that molt they will start to get their "hairs" (setae) on their body and look more like a proper baby tarantula. They will then be able to hunt, and eat tiny crickets.