What about critters?

I have been searching to see if this has already been covered since this is the first problem that pops into my head when considering pipes leaving my home. I don't want anything - not even bugs - being able to use that as a way to gain access to my home, or worse, get stuck in there. How do you keep the critters out while not having a gooped up screen?

Greywater diversion from showers and sinks typically happens after the p-trap, which is filled with water. This water seal prevents critters from entering the home, even in the unlikely event they crawled all the way up the pipes.

In the laundry-to-landscape system, where greywater is diverted from the discharge hose of the washing machine- there is also a water seal in the washing machine drain hose. If a critter made it that far it would not be able to pass the water seal, and it would get flushed out the next time someone did laundry.

So, in summary, you don't need to worry about critters coming in from a typical greywater system!