EMics use windscreens. Windscreens (otherwise known as pop filters) need to be replaced on a regular basis and each instructor should use their own windscreen on the club's EMic for obvious health reasons.
They can also be used with various other headmics such as those from Samson and other brands. Windscreens soften the 'plosive' vocal sounds and keep the wind out of the microphone if used outdoors.
Whether you call them foam balls, pop filters, mic tips, wind socks, mic protectors or even fluffy balls - These are what you need to make microphone use more hygienic and protect your microphone capsule.