CONTROL OF RODENTS AND PREDATORY ANIMALS 5 
Control workers should familiarize themselves with appropriate 
antidotes for poisons used and be in a position to administer them 
promptly should the necessity arise. 
RODENT-CONTROL OPERATIONS 
Extreme care should be exercised in handling poisons in rodent- 
control work. Prepared poisons should be placed in strong, properly 
labeled containers and should be distributed only to assistants work- 
ing under the direct supervision of bureau leaders or to responsible 
cooperators. 
Strychnine (in the alkaloid form) is the poison most largely used 
in rodent control, its speedy action making it one of the most 
humane. Moreover, numerous tests have shown that in the quanti- 
ties employed in control operations strychnine is relatively harmless 
to such gallinaceous birds as quail, pheasants, grouse, and domestic 
chickens. The smaller birds also are safeguarded because of the 
fact that the grains used in poisoned baits are of the large-kerneled 
kinds, such as oats, and contain a minimum of weed seeds and cracked 
kernels. Furthermore, in a large portion of the baits used the 
kernels are steamed, rolled, and flattened so that their increased size 
lessens their attractiveness to the smaller birds. 
The use of red squill in the control of house rats and mice is 
recommended, as it is an effective and specific poison for these 
rodents and relatively harmless to other forms of animal life. 
The use of thallium in rodent control will in some places succeed 
where strychnine alone fails. It should not be used, however, ex- 
cept to a very limited extent in follow-up operations against 
ground squirrels, prairie dogs, and rats. Such limited use of thallium 
should be guarded with the greatest care under close and fully com- 
petent supervision, as it is extremely dangerous to all life. Though 
thallium is highly effective in destroying rodents, it can not be over- 
emphasized that this poison is not to be recommended for general 
use, except to supplement strychnine in follow-up work. It should 
never be handled without careful consideration in each particular 
case of all the potential dangers involved. 
Arsenic, cyanides, and phosphorus should not be used or recom- 
mended for rodent control, as they are not now known to have any 
special advantages, and furthermore they may be a menace to other 
forms of animal life. Not only is phosphorus dangerous to bene- 
ficial wild life, but it is particularly unsafe because it sometimes 
causes fire. — 
Poisonous gases, which are efficient in the fumigation of burrows, 
grain bins, and garbage dumps, should be used only by = 
and experienced workers in rodent control. 
