69 



The rats being comparatively unmolested by both mongoose and snakes 

 have acquired the habit of making their nests in the trash about cane roots 

 in the plantations. It appears that there are two broods per year and 

 about three or four individuals in each brood. Though there is more or 

 less difficulty in dealing Math this pest it is certain that arsenic, if prop- 

 erly applied, will greatly reduce their numbers ; the seriousness of the pest 

 would be mitigated in a great degree were the planter to attend to this 

 matter immediately upon noticing the effects in the plantation. Strych- 

 nine has also been used in some cases; and a cheap variety of wire- 

 spring trap (costing some 20 centavos) may be used successfully on 

 some plantations. 



In dealing with this pest, either by poisons or traps, ordinary observa- 

 tion will disclose certain weak points, so to speak, in the life histor}^ 

 of the pest; for instance most rats use paths or runways in going to 

 and from their nests in the fields, and it is along these runways that 

 the traps or poisoned bait should be placed. 



A formula for poisoned bait, which has given excellent results in the 

 experiments by the Bureau of Agriculture, is made by simply mixing 

 about 5 per cent (by weight) of common powdered arsenic with some 

 food of which the rats are fond, such as ground coconut "meat," sweet 

 potatoes, or com meal. If corn meal be used it is necessary to boil the 

 meal until it is of the consistency of a thick mush, after which the 

 arsenic should be thoroughly mixed in. Barium carbonate is said to give 

 the same results if used in the same way as arsenic, but arsenic is cer- 

 tainly a more popular poison for this work. Strychnine is very effective 

 under favorable conditions but its use is always attended with consider- 

 able difficulty on account of its exceedingly bitter taste. If the rats can 

 be induced to eat some bait, such as camotes or chopped-up coconut, 

 containing even a small amount of strychnine sulphate, the result may 

 be better than with arsenic; a small amount of raw sugar mixed with 

 the bait is said to overcome, in a measure, the bitterness which would 

 otherwise, perhaps, prevent its being devoured by the rats. 



If the rats in the cane plantation have the habit of burrowing into 

 the ground, a direct method of eradicating the pest may be employed: 

 The rats frightened into their burrows, may be killed therein by simply 

 inserting about a tablespoonful of carbon bisulphide (preferably applied 

 on a small handful of crushed cane trash) and immediately stopping 

 the mouth of the burrow with earth ; if the burrow has no other opening 

 the rats will be immediately overcome by the poisonous gas. This 

 bisulphide method is particularly recommended for use in young cane 

 where the rats are forced to make retreats below the surface of the ground. 

 Wild pigs {Sus philippineiisis) . — Wild pigs are common in nearly 

 all sections of the Archipelago where there is sufficient forest or jungle 

 growth to furnish them adequate protection. Any cane field located 



