I get those when I accidentally step on a mimosa ( however you spell it. ), I remember that plant *mimosa* is a flower, or something like that, but it gets pretty damn near, and this flower cover up when it feels danger, when I step on those, they have sharp edges, ( their sharp edges has some kind of posin ), they usually hit my feets, at first. I just feel a ant bite at my feet, so I'm like 'whatever', then when I go to sleep, I see theres this very big hump like rashes and they start to spread and I have to itch my leg for the whole night untill the next morning, I got so fed up. I threw my pillow on the floor, stood up. Went to the toilet and washed my legs continously. After that day, I NEVER EVER WANT TO STAND NEAR LANDS WITH THAT KIND OF CRAP FLOWER!. unless I wear a shoe, lmao >_<