Pressure test system to observe leak
look at your engine oil you may have a leaking head gasket
you might have a blown head gasket and the coolant is leaking into the cylender and the engine is burning it.
antifreeze does not enter the engine at any time. locate and follow your radiator hoses and follow then and check for cracks or punctures.
Usually a leaking hose into or out of the water pump (depending on its location), or the water pump gasket.
Possible leaking hoses or water pump
Either one of the heater hoses are leaking or you have a freeze plug on the side of the engine leaking.
it is probably your freeze plugs
look on the ground and follow it straight up to the engine
Most of the time it is because the water pump is going out and it is leaking where the pulley is on the engine.
You can tell your rear engine is leaking by looking under your rear engine and see if there's drops hitting the ground.
Your car shouldn't "burn" antifreeze. If it actually is "burning" antifreeze then chances are you have a blown/leaking head gasket or possibly a cracked engine block which allows antifreeze to enter the combustion chambers. If your antifreeze is just disappearing then it is probably leaking out from somewhere. Possible leak areas to check out would be the radiator hoses, heater hoses, radiator, water pump, and the heater core. Most of the time if the heater core is leaking you'll be able to smell the antifreeze inside the car while the engine is running and the heater is on.