text: can you get bit and not know it? what would cause multiple red bumps, was worried about poison ivy but no, red litle bumps all over the calves. well depending on your location.. i am from texas and there are tiny bugs called "cheegers" there . they bite wherever something is tight. ie socks, waistband, bra line, etc... it could also be fleas. you don't usually know you are bitten by either of these until the next day or so when the ichy red bites appear.   hope this helps.