Microneedles find widespread use; researchers must perfect the techniques for optimally inserting them into the skin, and complete the integration of microneedles into a full diagnostic, monitoring or drug delivery system. Microneedles are expected to be less painful than conventional hypodermic needles because they are too small to significantly stimulate nerve endings. A painless "microneedle" that mimics the way a female mosquito sucks blood has been built by engineers in India and Japan. The needle could be used to draw blood, inject drugs, and as a glucose-level monitor for diabetics. The needle is also strong enough to penetrate as far as 3 millimetres into skin and reach capillary blood vessels. Its size compared to earlier models also means that surface tension effects are exploited further, and the same capillary flow that draws water up into trees helps draw blood into the microneedle.