Burrowing behaviors in Tsukuba Emotional rats and Activity mice were observed over a forty day period in a new type of soil which consisted of saw dust and absorbent cotton.
THE (Tsukuba High Emotional) rats converted the ground into a specific form called “gradient” (Photo 1), while HA (High Active) mice made a significantly larger number of nest chambers. Female rats were superior to males in the number of entrances and tunnel segments, and in the length of tunnels, although there was no sex difference in mice. The burrowing behavior was considerably different whether the overground was experimentally darkened or not. When the overground was darkened, subjects often remained on the surface of the ground.
Results regarding the influence of emotionality on burrowing behavior corresponded to the former study. Namely, THE rats were inclined to burrow faster, stayed underground longer, and were inclined to have higher operant levels of digging behavior.

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Three experiments were performed in this work. The purposes of the experimentation here were, first, to examine the possibility of the acquisition of avoidance response in crayfish, and secondly, to examine the structure of avoidance learning by comparing operant and Pavlovian contingencies within the chelipod-extention avoidance-learning paradigm.
In Experiment I, four groups were constituted by factorially combining the opportunity to avoid or not avoid the US and the opportunity to terminate or not terminate the CS. The results of Experiment I showed that avoidance responses were produced in crayfish within both operant and Pavlovian conditioning paradigms.
In Experiment II, subjects were divided into four groups, and each one of them was respectively exposed to the CSs alone, to USs alone, to the CSs and USs presented unpaired, and no stimuli, to examine the possibility of sensitization of response. The results showed that there was no tendency for sensitization of response to the CS to occur as a result of simple exposure to the CS alone, US alone, or CS and US presented separately.
In Experiment III, subjects were divided into four groups. In the first stage of the experiment, subjects were trained under avoidance conditions with or without CS termination by response, and then shifted under Pavlovian contingencies. The results indicated that avoidance performance of crayfish within the chelipod-extention avoidance-learning paradigm was produced by stereotyped defence reactions with apparent modifiability.

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The present experiment examined whether rats could learn serial pattern of reinforcement when they were trained with direct goal-box placement procedure (DP).
In the original learning phase, rats were placed directly in the baited goal-box. One group of subjects (Group M) received decreasing monotonic patterns in which the magnitude of each successive pattern item (food quantity) was decreasing ; that is, in a “less then” rule. The other group (Group R) received random patterns in which the items were arranged in random order.
In the transfer phase, rats were placed in the start-box and were required to run through the alley into the goal-box. Half of the rats in Group M (the M-M) learned a monotonic pattern, 14-7-3-1-0, while the other half (the M-NM) learned a nonmonotonic pattern, 14-1-3-7-0. Similarly, half of the rats in Group R (the R-M) learned the monotonic pattern ; the other half (the R-NM) the nonmonotonic pattern.
The results indicated that M-M learned the monotonic pattern faster than R-M, showing positive transfer, and for M-NM and R-NM, learning of nonmonotonic pattern was not observed before the last day of the transfer phase.
These findings suggest that rats can learn serial pattern even if they were not allowed to make instrumental running responses in the alley. Hence the rule-encoding theory on serial pattern learning seems to be applicable to the situation with specific training procedure (DP) employed here.

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