All of the Mouse-sized micro Bats use ultrasound calls for echolocation but fruitbats and flying foxes (megabats) have lost this ability. Although we can’t hear it, echolocation requires bats to scream at 130 decibels! That takes a lot of energy but the micro Bats are able to harness some of the muscular efforts from their wingbeats to generate the air pressures needed for their ultrasound calls. mega Bats flap their wings too slowly for this to work and considering that flying is already more tiring for them because they are heavier, it makes echolocation too exhausting to be worth it.
Engine oils play a crucial part in your engine’s functionality. Without the oil, your engine can become damaged fairly quickly and so it’s in your best interest to make sure that the engine oil is up to par. The oil in your engine makes sure that the all mechanical components are lubricated to reduce friction, wear and heat. The engine oil ensures that components don’t rub against each other and wear away. While it depends on how often you use your car, older engine oil doesn’t perform as well and so a regular change in engine oil is essential to the functionality of your car.