Rats can seriously damage rice and cause losses of 5% to 60%, or even 100% at seedbed. They are destructive in all stages of rice growth, reaching its peak at grain maturity stage.
Rats are difficult to manage because they reproduce rapidly in high numbers and their life span is long. Rats can be managed by limiting the availability of their food and destroying their breeding sites.
For effective rat management
- Know the signs of rat infestation. Observe for trails, v-shaped or 40o cut tillers and culms, and doughnut shaped damage.
- Encourage group or community action.
- Integrate all rat management options.
- Be proactive, not reactive.
Rat management options
1. Sanitation. Practice proper sanitation by removing all straw piles in the paddies after harvest and dry land preparation. Observe sanitation throughout the cropping season and fallow period to discourage rat breeding in the area.
2. Dry land preparation. This minimizes the presence of golden apple snails and weeds that serve as alternate food of rats.
3. Rat hunting and burrow management. Dig rat burrows and holes. Flush burrows and holes with water to force the rats to come out. Use flame thrower by placing the nozzle with flame into the opening of the rat burrow while other burrows are closed to suffocate the rats if water is limited.
4. Set up a Trap Barrier System (TBS)(see separate handout)
5. Use snap traps or other trapping devices. Use snap or live traps to control rats entering rice paddies. Put these traps along dikes where rat footprints and pathways are observed. (Note: This is not applicable to large areas; best used in storage areas and houses.)
6. Night hunting. Use head lamps in hunting rats at night. This method is best done during land preparation and before the rice canopy closes.
7. Water management. Increase water depth to 3-5 cm after the maximum tillering stage to minimize rat entry into the paddy.
8. Practice synchronous planting. Plant within a month of the regular planting time to limit availability of food during fallow period.
9. Minimize size of levees to 15 cm wide x 20 cm high when possible to discourage rats from making
burrows/breeding sites.
