What is this bug?! I see it on my back porch and it looks like a white bug but it has a yellow spongelike...?

Question:I know that this might sound weird but there is these bugs on my back porch that their feet and body are white/clear and they look to be carrying a yellow like sponge on their back. At first I thought that it was an ant carrying something but I tried to take this yellow spongelike thing off of its back and it turns out that it is connected and is part of the bug. The bug has a clawlike mouth too. Its weird and I want to know what it is. It seems harmless but I'm just curious!! Please, someone tell me what this weird bug is!!

Answers:
Take a photo so we can help ID it! That sounds like a really interesting bug! You could try asking this question in the biology section too!