These are called Lawn Shrimp or House Hoppers, scientific name: Talitroides Sylvaticus, a terrestrial crustacean. There are hundreds and hundreds of them laying dead in our back yard. I googled them and found out that they are very common in LA and Orange County, especially after rain. It's really gross when we let Wrigs out and he comes back covered in these crusty buggers. It could be worse. We could have these.