Rats are active throughout the year and in the past cold harsh winters were a natural method of keeping their number down. The milder winters of recent times have help rat populations thrive. By far the most common species of rat in Essex is the Brown Rat which has the scientific name of Rattus Norvegicus. By nature the Brown Rat lives underground which is one of the reasons they are found in sewers (one of the other names they are known by is the Sewer Rat).
Brown Rats are very good at digging and will create a complex of underground burrows where they have the chance. The entrances to these burrows are one sure sign that you have rats nearby.
If you have holes around your property that look likes those in the pictures, give St Georges Pest Control a call for professional advice.