摘要:
An ant-proof device that may confuse the sense of smell and sight of an ant includes an upper disk, and a lower disk. The upper disk is provided with upper annular walls forming upper annular channels each having an independent loop. The lower disk is provided with lower annular walls forming lower annular channels each having an independent loop. The upper annular walls and the lower annular walls are spaced in a staggered manner. Each upper annular wall may be extended into the lower annular channel, and a distance is defined therebetween. Each lower annular wall may be extended into the upper annular channel, and a distance is defined therebetween.
摘要:
A drawing instrument including two rulers each having a head portion, a circular protrusion formed on one of the head portions, and a circular recess formed in the other head portion for slidable engagement with the circular protrusion, the rulers are guided to rotate relative to each other by the slidable engagement between the circular protrusion and the circular recess. The head portions can be easily coupled together without additional tools or without additional coupling devices.