What bit me hard like a knot under it?

From the questions on the group

Question:

I don't have a clue what bit me. I found this on my leg 2 nights ago. It itches a little but its hard like a knot under it. Today its a little more painful than yesterday. Any ideas?

Answer:

I can conclude your complain in few lines:

You feel a tangled mass inside skin next day of the bite.

The itchiness and pain felt are of a little degree.

You have got only one single bite at a site of your skin.

The images show opening in the skin.

And therefore I can suggest:

Mosquito bite can be single and could be ignored until next night, and may be a boil formed, grown then gone that left such a wound in the site of the bite.

Spiders usually leave singular wound-like bite that has delayed allergic reaction which you may not notice pain and itching at the time of being bit.

Ants of some species can leave such wound-like single bites but they sting like a