Mice? bared cages?

I have 15 mice all together. about 12 of them can slip through cages with bars. how do I prevent this? thankx

Need smaller holes!
Get some hardware cloth (wire mesh) from ACE, True Value, or any hardware store and line the cage.
Got cats?

Get a cage with smaller gaps between the bars

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.

everytime I get smaller bars they just slip out.