In a trial with 14 pens with in each 20 turkey pullets (males, not treated) research has been conducted to the effect of feeding 12% insect larvae (Black Soldier Fly) on technical results and behaviour. The birds were kept until 5 weeks of age. The larvae fed groups ate less, had a higher growth rate, a better feed conversion ratio and a higher body weight at 5 weeks of age. Mortality was not different between the treatments. Compared to the controls the BSF larvae fed birds had less feather damage and less skin damage and performed less aggressive behaviour. Also they performed less foraging behaviour in the third and fifth week compared to the controls and a lower water intake. On the other hand at five weeks of age the BSF larvae fed birds had more footpad lesions than the controls, although litter quality did not differ between the treatments. In conclusion it can be stated that feeding insect larvae does give small advantages, but does not solve the problem of injurious pecking.