||The author had an information that a certain unknown animals had done severe damage to the fruits of strawberries under plastic-cover culture in Yoshii-Machi, Ukiha-Gun, Fukuoka Prefecture, from the l...atter part of January, 1963. The injurious animals were conjectured to be either mice or voles, judging from the faeces discovered at the farms and the method of eating the fruits (Plate 14, Figs. 1-3). The author carried on investigations twice at the farms of Oshiki (A) and Chitose (B) under the control of Chitose branch office of Yoshii-Machi Agricultural Cooperative Association. The one was carried on in the middle of February and the other in the latter part of March. Concerning the farm at Noraku (C), Mr. Gyotoku made an investigation on March 17, 1963 (Fig. 1). As the result, the author got three individuals of the Japanese mouse (♀2, ♂1), one of the Japanese harvest mouse (♀1) and one of the Japanese field vole (♀) from the farms belonging to A, B and C by means of snap-traps (Plate 14, Figs. 7,8 and Table 3). There were four kinds of strawberries cultured at the farms, i.e. "Kurume 102" (Benizuru-Norin 5), "Kurume 28" (Yachiyo), "Donner" and "Kurume 20" (Chiyoda). Among them, the three were under plastic-cover culture, while the rest (Kurume 20) was under spring culture (Plate 15, Figs. 1-9). The damage was discovored seriously at the farms where "Kurume 102" strawberries were cultured, and about twenty per cat of them were attacked by the above-mentioned mice and voles (Plate 14, Figs. 4-6 and Table 2). The total sum of damage was estimated at about 200,000 to 250,000 yen. Among individuals of these three species, the Japanese mice were regarded as the chief injurious ones, when the consideration was given to the collected number of this species (Table 3). There were some corn ricks on the farms which gave the favourite habitats to this kind of mice. So, at the end of the first investigation, these corn ricks were got rid of farms and the poison baits "Strong Ratemin" (zinc phosphide) were scattered there (Plate 13. Figs. 1-5). Visiting there in the second investigation, the author found a fair success in the above treatments for the mice and voles control (Plate 12, Fig. 9). Here, the author can conclude that clearing of circumstances of farms is the most essential to control mice and voles, and continual work for capturing them by means of poison baits and traps is as important as the first treatment, though these are worn-out sayings.