Seth Groats is a farmer who lives on the north-east side of Lumbridge (east of the river and north of the goblins). Seth is the father of Gillie Groats, a young Milkmaid in Lumbridge. He can be found inside the farmhouse on the road between Lumbridge and Varrock, next to the chicken shed.
You must run a favour for this man in the quest, One Small Favour in order to get him to give you a month's supply of chickens for the H.A.M. leader Johanhus Ulsbrecht. He will ask you to bring three steel bars to Horvik in Varrock, and will also request five chicken cages to transport the chickens.