1766. No insects were flying about and it occurred to me that ants might be bothering him, so I inspected the trunk of the tree and found ants going up and down in a thin column. (Not an unusual occurrence as regards trees here in general). I went to get "tree tanglefoot" and returned at 5:05. Rhody had been unable to stand the annoyance of the ants and had already left although the sun had already set. I applied the tanglefoot and went down to Rhody's house No.1; searched the vicinity and his regular routes to and from it without seeing him The brighter stars were out before 5:20, but no Rhody anywhere to be seen. With a powerful flashlight, the beam of which can be contracted to a slender shaft, I re-searched all probable locations, including the eucalyptus ( e. amygdalina) in which is his house No.2, inch by inch. This tree is in full bloom (numerous small white flowers in dense trusses like bunches of grapes). These flowers, with the tan colored twigs, a few brown leaves here and there amongst the green ones; the white, green and brown of trunk and larger limbs, all together form, when viewed by artificial light, a pattern into which Rhody would blend perfectly. Anyway I did not find him. Bearing in mind the roadrunner characteristic of comparative night-blindness (See these notes as regards this characteristic of Archie and Terry) I was curious as to how Rhody would overcome that handicap, hence the long search. About 7:15 I had Julio go down to No.1 and have another look there. He came back and announced that Rhody was in it at last. This must have been a performance of some difficulty for the bird in the dark. He surely was not there at 5:30, 56°. Here we have a case of Rhody's preferring the hazards of the dark rather than remain pestered (as I suppose) by ants in house 2. It seems reasonably certain that the ants were the motivating cause of this particular shift of sleeping place; and it may be that they have caused other changes by him. Now, why the ants, all of a sudden? Well, as stated, the peppermint gum is now in full bloom and presumably the flowers con- tain nectar. Again, although roadrunners keep their nests, roosts and the surroundings immaculate ( as regards droppings) I am reminded that, when R kills mice, they usually void urine and faeces and Rhody had had a mouse in his house a short time before. It is also possible that he may have carried a mouse there at some other time and abandoned it, so that the nest may not be clean now. This will be investigated. The Screech Owl. This owl, brought me for attention some time ago--see notes-- apparently has nothing the matter with him. He sleeps all day in a house within the cage and is given live mice to eat. He began ejecting pellets at once and has continued regularly. At night he comes out of his house and sits on a perch. Rapid pupillary action of owl's eyes. In looking for Rhody, as reported above, I looked in the cage also and was mildly surprised to see the owl staring at me with pupils extremely contracted, giving him an odd appearance. I ex- perimented by flashing the light off and on end was amazed at the rapidity of the reflex controlling this pupillary action. It is so rapid that, on turning on the light, I could get but a fleeting glimpse of the pupils in their expanded state. Almost instantly they would contract. As a guess I would say the duration from full dilation to complete contraction was of the order of 1/5 second. (But this is only a guess).. This proved a fascinating game which the owl did not seem to mind in the least. The mice vs Rhody. Due to Rhody's autumnal decline of appetite and the extra- ordinary fecundity of the last batch of mice obtained from the Univer