Nucleus box designs vary and most do not have the ventilation required for our products, even for a single strip treatment. Without a full bottom entrance (full width of a full size hive, ½inch(1.3cm) high), hive ventilation during treatment is compromised. Our products should only be applied on single or double brood chamber standard Langstroth equipment or equivalent (e.g. Dadant, British National). The Honey bee colony cluster must cover a minimum of 6 brood frames (approximately 10,000 bees). If you move your nucs into full size brood chambers and allow them time to expand to a full six frames, you can then treat with our products.