§ Mr. Paterson
To ask the Secretary of State for Environment, Food and Rural Affairs what assessment has been made of whether there are(a) physiological and (b) neurological differences between rabbits and moles, and badgers, which would affect their response to poisoning by fumigants, in terms of the distress and pain caused. 
§ Alun Michael
All pesticides used as fumigants are subject to strict regulatory control and must be approved by Ministers before they can be marketed or used in the UK. Those seeking approval for such products are required to provide data to ensure that the product is safe, effective and humane.
No specific assessment is made of physiological or neurological differences between rabbits and moles in response to poisoning by pesticide fumigants.
However, the Advisory Committee on Pesticides considered a report in 1996 on humaneness of vertebrate control agents, which resulted in the loss of one pesticide fumigant substance and approval for the remaining pesticide fumigant products to continue. Data on humaneness of pesticide fumigants in relation to the target test species, such as rabbits and moles were considered.
Use of pesticide fumigants against badgers, which are protected species, is not permitted, except in special circumstances, and as such would not have been considered.