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poisonous qualities for some time ; they are also less luminous in the
dark, and, therefore, more readily taken by rats. These baits are placed
about 20— 40 to each house, in places that are practically only accessible
to the rat, which excludes all danger to children and domestic animals ;
such places are in the rat holes themselves, behind boxes, underneath
oorn bins, on the tops of the wall supporting the roof, etc. In any
town or village as large an area as practicable should be treated in this
way, at a single operation, in order to give as great a shock as possible
to the rat population before they recognise the dangerous character of
the bait. Baitings on successive days have been found to have no
advantage over the single baiting method. Baits are prepared in the
morning and laid in the afternoon and evening. For the preparation
and placing of the baits a compounder and three coolies are usually
employed. Such agency can ordinarily prepare and lay, in a day, from
9,000 to 12,000 baits, that is to say, they can thoroughly treat a village
of 400 houses, approximate population 2,000—2,400. A Hospital
Assistant or Assistant Surgeon should ordinarily be in charge of one or
more gangs, such gangs operating in large villages or adjacent small
villages. Where the active co-operation of the inhabitants is obtained,
more work than this can be done.
If the baits are properly placed, they may be allowed to remain,
instructions being issued that all village sweepings for the next week
. should be burnt ; otherwise baits will find their way to the village
rubbish heap, where fowls, pigs, etc., may find and eat them. The dead
rats found are collected and buried or burnt.
A search for dead rats should be made every morning for six
days after the poisoned baits are put down.
(c) The frequency with which this procedure should be repeated
depends on the rate at which the rat population recover from the shock
caused by the poison, but on the whole a month should elapse before
any fresh trial to poison rats of any particular neighbourhood is
attempted.
(d') This method of poisoning should be made use of whenever
an epidemic is likely to occur, but in all places where a recrudescence ia
expected in the cold weather two attempts should be made, one in the
month of October and the other in November.
(2) Trapping :—
(a) Trapping of rats should go on at all times within infected
areas ; but it is occasionally well to leave certain areas unmolested
for a week or two so that the rats may not become too familiar with
the trap.
(b) The best trap is the " Wonder " trap or one that works on
this principle ; it should however be made of steel wire, not galvanised
iron, as a strong rat can bend the latter. The best made traps of this
nature are made at the North-West Frontier Iron Works, Rawalpindi.
They cost Rs. 2 each and the makers pay carriage if a large
number is ordered. The Plague Research Laboratory, Parel, Bombay,
will supply a small number to any local body, but the carriage from
Bombay will have to be paid by the purchaser. Other traps which work
on this principle and which have been found useful against rats can be
obtained from the Army and Navy Stores, Bombay, from Messrs.
Oakes"& Co., Madras, and from Saiyid Abdul Karim Sahib, No, 6,
K. Shanmugaroyan Street, Georgetown, Madras.