Clothing can sometimes help prevent mosquito bites, but it largely depends on the material and how it fits against the body. Mosquito bites can easily penetrate clothes when the fabric is thin and snugly fitted.
Even wearing long sleeves and pants might not help if the material is thin and stretchy. Loose and thicker fabrics offer better protection compared to tightly fitted clothing made with fine material.
The Short Answer
Yes, mosquitoes can bite through thin, stretchy, or tightly-fitted clothing. Their proboscis is only about 100 microns wide (same as human hair). Best protection: thick, loose-fitting, light-colored fabrics like denim or nylon ripstop.
