Anything that lived ( meaning anything that has carbon in it)can be composted. At home 'cold composting'is common,and include worm farms.Air,water and food is needed.If the compost gets too damp,it will smell and need a stir.This can happen if soogy material is added,or even as gravity settles the pile down over time. 'Hot composting' can mean temps greater than 60 degrees and is used to process large amounts o waste. Compost is safe,rich in nutrients and is terrific for the garden.It improves drainage in heavy soil,retains water in light soil,improves aeration,prevents crusting and keeps the soil warmer in winter and cooler in summer.All of these things improve plants resitance to disease. PERMACULTURE PRINCIBLE :produce no waste