Drain Survey in Chard, Somerset: Finding the Entry Points Behind a Long-Running Rat Infestation

Warren Smyth — Thu, 01 Oct 2026 09:16:11 +0000

A rat infestation that keeps returning needs more than repeated treatment—it needs a thorough investigation into how the rats are getting inside.

Six to Eight Years of Recurring Rat Problems

Smyth Pest Control was called to a block of flats in Chard, Somerset, where residents had reportedly experienced rat problems for approximately six to eight years. Several pest control companies had attended during that time, but the recurring infestation remained a concern.

Our investigation identified drainage access points by our second visit. We then fitted one-way rat blocker valves to the relevant drain connections to help prevent rats entering the property through those routes.

A persistent rat infestation can be distressing for residents and difficult for landlords and property managers to manage. When activity returns after treatment, an important question is: What is allowing more rats to enter the building? At this Chard property, the reported history suggested that we needed to investigate the access routes as well as address the infestation itself. Our approach focused on identifying how rats could reach the building and what practical measures could help prevent further ingress.

What Our Drain Survey Found

As part of our investigation, Smyth Pest Control completed a drain survey to examine the drainage serving the block of flats.

By our second visit, we had identified a number of drain outlets and connections that were allowing rats to gain access towards and into the property.

These findings provided a clear explanation for how the infestation could keep recurring. While pest control treatment could address rats already present, the drainage routes also needed attention to help stop further entry.

For this property, investigating below ground was an essential part of understanding the wider problem.

Fitting One-Way Rat Blockers

Following the survey, we fitted one-way valves, commonly known as rat blockers, to the relevant drain connections.

Rat blockers are designed to allow wastewater and waste to flow out through the drainage system while preventing rats from travelling back towards the property through the protected pipework.

The purpose of the installation was to:

Restrict the drainage access routes identified during our survey.
Help prevent future rat ingress through those connections.
Support the wider pest control work with a physical preventative measure.

Correct positioning matters. A rat blocker needs to be suitable for the pipework and fitted in the appropriate location. Ongoing inspection and maintenance are also important, and any drainage defects requiring repair should still be addressed.

Why Repeated Rat Treatment May Not Be Enough

Trapping and baiting can play an important role in controlling an active infestation. However, if an entry point remains accessible, further rats may enter.

This case highlights the value of combining rat control, investigation and proofing. Identifying an access route gives the property owner or managing agent something specific to address, rather than relying solely on further treatment whenever activity returns.

At the Chard block of flats, the drain survey allowed us to move from managing recurring activity to taking targeted action against the identified entry routes.

When Should You Consider a Drain Survey for Rats?

A drainage investigation may be worth considering when:

Rats repeatedly return following pest control treatment.
Activity continues without a clear external entry point.
Rats are suspected beneath floors or within building voids.
A block of flats has a long history of recurring infestations.
Previous treatments have reduced activity without explaining how rats are entering.

These signs do not automatically mean the drains are responsible. A thorough survey helps establish whether drainage is contributing to the problem and what action is appropriate.

Drain Surveys and Rat Control in Chard, Somerset

Smyth Pest Control provides rat control, CCTV drainage investigations and rat blocker installation in Chard and the surrounding areas, alongside pest control services across Somerset, Dorset and Devon.

With over 25 years of pest control experience, we understand the importance of investigating the cause of a recurring infestation and giving clients clear, practical advice.

Whether you are a homeowner, landlord, resident or managing agent responsible for a block of flats, we can investigate persistent rat activity and recommend suitable treatment and preventative measures.

If rats keep returning to your property in Chard, contact Warren to discuss a drain survey and a targeted plan to address the access points.

Call Warren: 01460 261615 Request a quote

See our pest control services in Chard.

Drain Surveys - Smyth Pest Control