When ordering livestock from Dr. F&S, the order is sent overnight delivery. It is only shipped on days such that it will arrive to you overnight. If I remember correctly, this means that orders will only be shipped Monday-->Thursday.
You must have it delivered to an actual person. If you can't be at home and sign for it, you should have it delivered to work. Basically, they want to make sure the livestock isn't sitting boiling to death on your front porch (or conversely, freezing to death in January).
I've ordered from them once and was quite pleased. There was a delay caused by the shipping company which resulted in my overnight order not making it to me for 2 days. As soon as Dr. F&S realized the order was delayed, they contacted me to notify me of the delay and to reassure me that if any organisms were struggling health-wise because of the delay that they would be replaced free of charge. Despite the delay, every single organism was alive and doing well. I did leave work early that day though to get my fish, snails, and other organisms (I got one of their algae-eaters "kits") in the tank that much earlier.
In summary, I would definitely consider ordering livestock from them in the future.