Feather pecking (FP) is a major problem in cage and free-range housing systems. In free-range systems FP is more difficult to control. Legislation concerning animal welfare is becoming more strict in the European Union and this has resulted in more free-range housing systems. It is not known why victim is being pecked. It could be that a bird is genetically predisposed to be pecked. To study the genetics of FP behaviour, a large F2 population of 630 hens was generated from a cross between two commercial laying lines differing in their propensity to feather peck. Traits such as receiving gentle FP, receiving severe FP, and receiving aggressive pecking were measured at 6 and 30 wk of age. Furthermore, receiving toe pecking (TP) was measured at 30 wk of age. A significant Quantitative Trait Loci (QTL) on GGA1 and three different suggestive QTL were identified on GGA2, GGA6, and GGA7 for receiving gentle FP at 6 wk. For receiving gentle FP at 30 wk of age, a suggestive QTL on GGA5 was detected. For receiving aggressive pecking, a suggestive QTL was detected on GGA3. For receiving TP, three suggestive QTL were detected on GGA1, GGA5, and GGA23, respectively. The different QTL detected for receiving gentle FP at different ages indicate that this trait is regulated by different genes in young and adult hens.