dried boiled rice
糒 centers on dried boiled rice, a preserved food made by cooking rice and then drying it for storage or travel.
糒 combines 米 (rice) with a phonetic element that also suggests preparation or storage. The exact historical development of the right side is uncertain, but the character is associated with dried cooked rice.
The left side is 米 (rice). The right side looks like a container with a lid and something inside, like a packed lunch. Picture cooked rice being dried and stored in a container for later use.
For ビ, imagine a bee (ビ) buzzing around the dried rice, trying to get a taste. The bee sound cues ビ while the rice is being dried.