Chigger bites in and of themselves are not noticeable.

More Info:  Once a chigger pierces the skin of its victim, it will inject an enzyme through its saliva that will kill the surrounding tissue.  This causes a stylostome to form that acts as a feeding tube for the chigger to suck up liquefied tissue.  This often appears on the skin as a red, blister-like welt.  The longer the chigger feeds, the larger the welt becomes. 

Where Do Chiggers Bite?

Chiggers are microscopic and have a difficult time penetrating the skin, which is why the bites are often found around areas of thinner skin such as wrinkles or folds.  Common bite sites include the ankles, behind the knees, groin area, and under the arms. 

How to Tell If It Is a Chigger Bite

The red welt caused by a chigger bite is often mistaken for a mosquito bite.  Unlike a mosquito bite, a chigger bite will continue to grow as long as the chigger is still feeding.  If the welt becomes large enough, you may be able to see a white dot at the center of the bite.  The white dot is not the chigger but the stylostome that has formed under the skin. The intense itch caused by a chigger will usually cause the host to scratch which in turn will disengage the chigger.