There are several synonyms that can be used in place of the phrase "be swarming with." Such alternatives include the words "teem," "abound," "overflow," and "brim." Each of these synonyms conveys a sense of abundance and vitality, suggesting that the place in question is brimming with life or activity. Other possible synonyms might include "buzz" or "hum," which can be used to describe a place that is bustling with energy and movement. Whether you prefer to use "be swarming with" or one of its many synonyms, the important thing is to choose a phrase that effectively conveys the idea you want to express.