There are scientists with different character skins; some may have masks on, some may be larger than others, and so on.
They are affected by every jetpack Barry uses other than the Rainbow Jetpack and the Golden Piggy Pack. When Barry is in their presence (with a potentially dangerous jetpack), they will flee or crouch into a fetal position. They may also take off running, often times running into the zappers. Even when the player is using the Rainbow Jetpack, some will occasionally walk into the zappers and die. You can high-five scientists for one of your challanges. When using a vehicle, they can be crushed when landed on, or hit when crouching. When crushed, scientists burst to pieces, and float slowly to the ground. This also happens when they are shot with the shotgun that comes with the Bad As Hog. They can be removed via the Nerd Repellent gadget.