From white lies to massive deception, you to know when someone is lying to you. There are actually four telltale things to look for and analyze if you think there are lies being told. While these habits might not prove that lies are involved, clusters of behaviors could at least tip you off that something is wrong and further investigation is needed.

Since lying takes more concentration than just telling the truth, the pupils will be more dilated than normal. This is one of the most common ways to tell if someone isn’t being honest. Unlike telling a lie, its nearly impossible for someone to control their pupils, so dilation will happen naturally acting as a great indicator of truth or lie.

Can’t get close enough to look into their eyes? Lying can also be detected through increased movement of the feet. Since lying normally makes people nervous, they will often expel anxiety by shaking, tapping or shuffling their feet. In an attempt to relax in an intense situation, the liar might extend out their feet or stretch out their toes.

While telling a story, if you think the person you are talking to is lying, pay close attention to the body language versus their words. Are they congruent? If they are talking about being happy and satisfied are they sitting up straight, engaged and using their hands lightly to emphasize? If they are talking about how happy they are but are hunched over, looking at the floor and lack body movement, something might be amiss.

Also keep in mind when asking questions that coming up with a lie always takes more time than just spitting out the truth. Simple questions about time, date and location should be quickly and easily answered. If someone delays or avoids the question, they could be just looking for time to come up with a realistic lie.

If you believe someone is lying to you check his or her eyes. Also watch their feet and body movement when they talk. Lastly, pay attention to lag in response times when talking face-to-face. While these signs may not be definitive proof, they can be a good indication about whether deception is in the air and if further investigation should be sought.