Rat Update 2 June

The Conservators of Therfield Heath and Greens intend to recommence the use of rodenticide to control the three rat colonies that live in the New Road Car Park. 

The Conservators have been in communication with our pest control expert. Natural England and the Health and Safety Executive including the Wildlife Incident Investigation officers to agree an appropriate means of removing the rat infestation. 

The human generated food source has been removed and the rat population is now approaching parked cars looking for food. As such the rat extermination is an urgent priority to protect people using the car park. 

We have explored the trapping of rats with devices fitted inside the 4 bins. This has been discounted as published data has indicated that the rat population is breeding faster than we can catch them safely with traps. 

Closing the car park is not a feasible option for two reasons, a) road safety due to the displaced cars parking on the road and b) it doesn’t deal with removing the rats. 

We have considered catching rats with terrier dogs, again we’ve concluded that this is not appropriate due to the amount of people and other dogs walking on the heath. 

We have concluded, after taking advice from the HSE, Natural England and our appointed pest controller that a targeted short period of rodenticide will exterminate the rats quickly.  

The Conservators accept that this approach does present a small risk to other wildlife including birds of prey. However daily inspections of the car park and surrounding area by at least one Conservator to remove any visible dead rats and regular monitoring by our pest controller will reduce this risk to an acceptable level. This approach meets the requirements of the Health and Safety Executive and NHDC. 

If anyone has any question on this approach, please email clerk@therfieldheath.org.uk and we will respond as soon as possible.  We would like to thank the public for their support, especially how good everyone has been about taking litter and waste food home to remove the rat food source. It reminds us how much the public cherish the Heath and are willing to work with us to keep it such a beautiful place.

Thank you

11 June

Early indications have shown that since we sealed up the bins at the end of last week, the litter and discarded food problem has reduced to almost zero. So far, the public are taking their rubbish away with them, which has surprised us and this is the opposite of what we were advised to expect from experts. We thank everyone for taking their litter away with them.

Hopefully, this will continue, and it will protect the Heath from the negative impact of litter being left on the floor or in bins.

What are we aiming to achieve:-

1. Eradication of the rats which are causing a risk to humans

2. Permanently remove the food source to avoid a similar problem in the future.

3. Keep the car park open for visitors and avoid cars parking on the road and the unintended road safety problems that would cause

What have we done previously:-

1. Tried to remove the food source by making amendments to the bins to stop the rats gaining access to the discarded food

2. Place poison bait under the bins

This was not successful. The rats were still gaining access to the bins, which has not removed their ability to access the food source. The result is that the rats were not eating the bait.

What are we doing now:-

1. We have sealed up the bins so waste food and litter cannot be put in the bins and the rats can’t gain access

2. Asked all visitors to take their rubbish away when they leave

3. Removed the poison temporarily whilst we monitor to see if the litter and discarded food is reducing and to avoid exceeding the amount of time poisoning can be carried out by law

4. Asked McDonald to continue with their twice daily litter picks

5. New rodent proof  bins are on order (delivery time 3-4 weeks)

6. Monitoring the situation for the next 3 weeks

What will we do next:-

1. Assess if the litter and discarded food source problem reduces

2. Assess if further baiting with poison is required

3. Monitor the situation and assess if the rat population is reducing

4. Make a decision on whether to install new bins based on how much litter the public leave in the car park or remove the bins entirely.

5. Continually monitor whether we need to temporarily close the car park


Confirmation from the Health and Safety Executive regarding Wildlife Incident Investigation Scheme that consideration was given to the Hierarchy of Control as identified in the CRRU Code of Best Practice prior to application of the rodenticide, and that when the application of the rodenticide was begun it was being applied in a manner intended to minimize the risks to humans, companion animals and wildlife – Use of rodenticide at Therfield Road car park – Reference: 0705BXM21-01 –