Hello, my name is Dr Helen, I hope I can help you today.
These do not sound like nits.
Nits live only in the hair and cannot fly or jump.
What you are describing sound more like fleas...do you have pets by any chance? If so they are the most likely source and fleas do bite and jump. Fleas cannot live on humans but they can land on us and bite.
If you have a pet then you need to give them flea treatment (available from vets or pet shops.) Then wash their bedding and anything else they sleep on. You can also buy a spray in pets shops to use round the house on carpets and soft furnishings to kill any fleas off.
You can use a cream like sudocrem (available in Boots or any chemist quite cheaply) on the bites themselves to help them go away.
I joined JustAnswer in June 2013 and am a UK doctor. I have been qualified for 23 years and have widespread experience in GP and cancer care.