Backyard debate : To bait or not to bait

There is a rat fight going on between the Environmental Protection Agency and some pest control manufacturers that could affect Maryland backyards. At issue is whether residents will continue to be able to kill rats with certain potent poisons, which can now be purchased at hardware stores and are strong enough to dispatch the rodents after they make one visit to a poisoned meal. The EPA said this week it wanted to prohibit residential consumers from administering these poisons, making the stronger stuff available only to farmers and professional exterminators. At least two affected companies are challenging the decision.

The EPA plan would allow home owners to administer substitutes, less toxic poisons the kind that require the rodents to feed several times before expiring.


Another issue is how these doses are served up. Now some of the one-and-done poisons are pellets, sometimes served in trays or in packages that the vermin chew through. The EPA would ban pellets, which its says pose the danger of small children and household pets nibbling on them, and require all rat poisons to served in blocks secured in so-called "bait stations." These are plastic enclosures with latched and sometimes locking lids.

Two manufacturers, Liphatech Inc and Reckitt Benckiser, have challenged the EPA, saying these prohibitions are unnecessary and will make rat control needlessly expensive. The matter will now likely go to an administrative body, composed of scientists, who will make a ruling. This could take two years. In the meantime the companies will continue to sell their products. There is, in other words, no need to hoard rat poison.


To bolster its case for the ban, the EPA says children are particularly at risk from rat poisons and cites statistics saying that nationally poison control centers receive between 12,000 and 15,000 reports of children under six being exposed to them. However the Maryland Poison Control Center reports that such instances are usually minor in nature without long-term health consequences to the child. Even though the chances are slight that children could seriously harm themselves by ingesting these poisons, it seems wise to make sure they are delivered in tamper-proof containers such as the bait stations. Already types of these devices are sold in Baltimore hardware stores for $16 to $18. Chunks of poison are secured on spikes inside a box. The bait stations aren't pretty, and they announce to the world that you are having a rat problem, but they do the job.

Requiring that rat poisons are administered in some type of closed, tamper-proof containers makes sense. But insisting that poisons now available to consumers can be used only by professional exterminators seems to be overreaching.

Experts on all sides of this issue agree that poisoning is only one of several tools that need to be employed in the battle against rat infestation. Equally important are removing the sources of food, such as garbage cans without lids, and eliminating rat-friendly habitats such as tall grasses and weeds. Some of the best brains at Johns Hopkins — an institution with a long and distinguished line of rodent researchers — concluded some time ago that rat populations cannot be controlled simply by poisoning. One study found that when poisoning reduced one neighborhood's rat population by half, the surviving rats increased their birth rate to make up for the lost numbers.

Rats are not welcome companions, but they are resilient. Keeping them at bay requires good sanitation and housekeeping practices and prudent use of poisons administered in closed, tamper-proof containers.

Rob Kasper