HUSBANDRY, EQUIPMENT, AND PROCUREMENT OF MICE 553 



the pellets into a trough located below the hole. The shape of the trough is designed 

 to fit the scoop used to dispense the food. The trough can be detached and cleaned 

 each time the container is emptied. The entire dispenser is suspended from two 

 upright angle iron supports fastened to the side of the table. The bottom of the trough 

 should be about 2 or 3 inches above the tabletop to facilitate cleaning. 



Tag holders. — Various methods are used to attach cage identification tags or record 

 cards. If the tag holder is attached to the cover of the cage it can be moved from 

 one cage to another at cage-changing time. Covers need not be changed as often as 

 the cages unless the food in the hopper becomes accidentally soiled or wet. Tag 

 holders for our colonies are made of sheet aluminum. They are designed to clip 

 onto a transverse bar about 1 \ inches from the front edge of the cover. The edges of 

 each holder are bent over at the bottom and the two sides to hold the card in place. 

 Tag holders can be made in any size to accommodate the identity tags or record 

 cards which are used. A convenient model is designed to hold a 3 by 5 inch card. 



Tables and carts.- — Tables for use in mouse rooms should have smooth surfaces to 

 prevent accumulation of dirt. It is preferable to have separate tables for use in chang- 

 ing cages and for record keeping, but if both of these functions are performed on one 

 table, the table should have space for laying out the record books or cards. The 

 tables should have metal surfaces (either stainless steel or galvanized iron sheets). 

 The legs and other framework can be steel angles or pipe welded into a solid unit. 

 Tables with large-diameter wheels (4 or 5 inches) are easiest to move. The height of the 

 tables should be governed by the height of the people who use them. 



Tabletops should be about 42 inches long and 30 inches wide. Two shelves under 

 the top will make it possible to carry cages with covers and water bottles attached 

 on each shelf. (Although mice may seldom be removed from the room it may be 

 necessary when experimental treatment is to be administered.) The width of the table 

 should be small enough to permit passage through the aisles between cage racks even 

 when a stack of cages on a dolly is standing at one side of the aisle. 



Tables for changing cages should have a food dispenser attached on the right-hand 

 side (left side if the caretaker is left-handed). The food dispenser previously described 

 is quite large and overhangs the top surface of the table. Such a food dispenser 

 makes the table too heavy for general use. 



Washing machinery. — The size of colony will determine, to a large extent, the methods 

 to be used to sanitize the equipment used in the mouse room. If only one person is 

 needed to take care of the mice and to wash the cages and water bottles, extreme caution 

 must be exercised and careful instructions must be given to be certain that the clean 

 and dirty areas are not violated. It is much more efficient to have two people working 

 in the washing area, one at the dirty end and the other at the clean end. If the 

 colony is very small, two workers should still be used in the washing area even if on a 

 part-time basis. 



Machinery for washing cages should be adaptable to the clean-corridor system. 

 That is, the machines themselves must function as the division point between the two 



