As warmer weather arrives in the UK, rat activity increases, particularly from March to October, making homes more susceptible to infestations. To combat this, cayenne pepper serves as a highly effective and inexpensive natural deterrent. The intense spiciness of cayenne irritates rats' sensitive noses, prompting them to avoid areas with strong chilli scents. A simple DIY rat repellent can be made by boiling 1 tablespoon of cayenne pepper powder or chilli flakes in 1 quart of water, then adding a dash of dish soap before transferring it to a spray bottle. This mixture can be sprayed in areas prone to rat activity, ensuring hard-to-reach spots are covered. Additionally, scattering cayenne pepper around potential entry points, such as gaps around pipes and doors, can further deter rats. It's important to reapply the mixture after heavy rainfall and to keep it away from children and pets due to potential irritation.