If you don’t clean your gutter the primary problem to arise will be blocked gutters and downspouts meaning that there is going to be standing water gathering in your gutters will become very dirty and mould will start to form. Mould can be the host for many health problems if it does get inside of the home. Mould is also very tricky to get rid of and can be very expensive. Gutters are a huge magnet for bacteria, birds, mice, rats and lots of other animals. Warm moist rotting leaves are a source of nourishment for many critters and once they’ve worked their way into the gutters the next will be in your home.